diff --git "a/test_final_limo.jsonl" "b/test_final_limo.jsonl" new file mode 100644--- /dev/null +++ "b/test_final_limo.jsonl" @@ -0,0 +1,817 @@ +{"question":"Find the last three digits of the product of the positive roots of $\\sqrt{1995}x^{\\log_{1995}x}=x^2.$","solution":"25"} +{"question":"For how many pairs of consecutive integers in $\\{1000,1001,1002^{}_{},\\ldots,2000\\}$ is no carrying required when the two integers are added?","solution":"156"} +{"question":"Given a triangle, its midpoint triangle is obtained by joining the midpoints of its sides. A sequence of polyhedra $P_{i}$ is defined recursively as follows: $P_{0}$ is a regular tetrahedron whose volume is 1. To obtain $P_{i + 1}$ , replace the midpoint triangle of every face of $P_{i}$ by an outward-pointing regular tetrahedron that has the midpoint triangle as a face. The volume of $P_{3}$ is $\\frac {m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"101"} +{"question":"Set $A$ consists of $m$ consecutive integers whose sum is $2m,$ and set $B$ consists of $2m$ consecutive integers whose sum is $m.$ The absolute value of the difference between the greatest element of $A$ and the greatest element of $B$ is 99. Find $m.$","solution":"201"} +{"question":"Let $S$ be the set of all positive rational numbers $r$ such that when the two numbers $r$ and $55r$ are written as fractions in lowest terms, the sum of the numerator and denominator of one fraction is the same as the sum of the numerator and denominator of the other fraction. The sum of all the elements of $S$ can be expressed in the form $\\frac{p}{q},$ where $p$ and $q$ are relatively prime positive integers. Find $p+q.$","solution":"719"} +{"question":"Let $n=2^{31}3^{19}.$ How many positive integer divisors of $n^2$ are less than $n_{}$ but do not divide $n_{}$ ?","solution":"589"} +{"question":"Given that $\\sum_{k=1}^{35}\\sin 5k=\\tan \\frac mn,$ where angles are measured in degrees, and $m_{}$ and $n_{}$ are relatively prime positive integers that satisfy $\\frac mn<90,$ find $m+n.$","solution":"177"} +{"question":"The solid shown has a square base of side length $s$ . The upper edge is parallel to the base and has length $2s$ . All other edges have length $s$ . Given that $s=6\\sqrt{2}$ , what is the volume of the solid? [asy] import three; size(170); pathpen = black+linewidth(0.65); pointpen = black; currentprojection = perspective(30,-20,10); real s = 6 * 2^.5; triple A=(0,0,0),B=(s,0,0),C=(s,s,0),D=(0,s,0),E=(-s\/2,s\/2,6),F=(3*s\/2,s\/2,6); draw(A--B--C--D--A--E--D); draw(B--F--C); draw(E--F); label(\"A\",A, S); label(\"B\",B, S); label(\"C\",C, S); label(\"D\",D, S); label(\"E\",E,N); label(\"F\",F,N); [\/asy]","solution":"288"} +{"question":"A drawer contains a mixture of red socks and blue socks, at most 1991 in all. It so happens that, when two socks are selected randomly without replacement, there is a probability of exactly $\\frac{1}{2}$ that both are red or both are blue. What is the largest possible number of red socks in the drawer that is consistent with this data?","solution":"990"} +{"question":"Let $A_1A_2A_3\\ldots A_{12}$ be a dodecagon ( $12$ -gon). Three frogs initially sit at $A_4,A_8,$ and $A_{12}$ . At the end of each minute, simultaneously, each of the three frogs jumps to one of the two vertices adjacent to its current position, chosen randomly and independently with both choices being equally likely. All three frogs stop jumping as soon as two frogs arrive at the same vertex at the same time. The expected number of minutes until the frogs stop jumping is $\\frac mn$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"19"} +{"question":"Lily pads $1,2,3,\\ldots$ lie in a row on a pond. A frog makes a sequence of jumps starting on pad $1$ . From any pad $k$ the frog jumps to either pad $k+1$ or pad $k+2$ chosen randomly with probability $\\tfrac{1}{2}$ and independently of other jumps. The probability that the frog visits pad $7$ is $\\tfrac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"107"} +{"question":"Given a rational number, write it as a fraction in lowest terms and calculate the product of the resulting numerator and denominator. For how many rational numbers between 0 and 1 will $20_{}^{}!$ be the resulting product?","solution":"128"} +{"question":"Initially Alex, Betty, and Charlie had a total of $444$ peanuts. Charlie had the most peanuts, and Alex had the least. The three numbers of peanuts that each person had formed a geometric progression. Alex eats $5$ of his peanuts, Betty eats $9$ of her peanuts, and Charlie eats $25$ of his peanuts. Now the three numbers of peanuts each person has forms an arithmetic progression. Find the number of peanuts Alex had initially.","solution":"108"} +{"question":"The area of the smallest equilateral triangle with one vertex on each of the sides of the right triangle with side lengths $2\\sqrt3$ , $5$ , and $\\sqrt{37}$ , as shown, is $\\tfrac{m\\sqrt{p}}{n}$ , where $m$ , $n$ , and $p$ are positive integers, $m$ and $n$ are relatively prime, and $p$ is not divisible by the square of any prime. Find $m+n+p$ . [asy] size(5cm); pair C=(0,0),B=(0,2*sqrt(3)),A=(5,0); real t = .385, s = 3.5*t-1; pair R = A*t+B*(1-t), P=B*s; pair Q = dir(-60) * (R-P) + P; fill(P--Q--R--cycle,gray); draw(A--B--C--A^^P--Q--R--P); dot(A--B--C--P--Q--R); [\/asy]","solution":"145"} +{"question":"Three vertices of a cube are $P=(7,12,10)$ , $Q=(8,8,1)$ , and $R=(11,3,9)$ . What is the surface area of the cube?","solution":"294"} +{"question":"Define a positive integer $n^{}_{}$ to be a factorial tail if there is some positive integer $m^{}_{}$ such that the decimal representation of $m!$ ends with exactly $n$ zeroes. How many positive integers less than $1992$ are not factorial tails?","solution":"396"} +{"question":"Find the least positive integer $N$ such that the set of $1000$ consecutive integers beginning with $1000\\cdot N$ contains no square of an integer.","solution":"282"} +{"question":"Consider the points $A(0,12), B(10,9), C(8,0),$ and $D(-4,7).$ There is a unique square $S$ such that each of the four points is on a different side of $S.$ Let $K$ be the area of $S.$ Find the remainder when $10K$ is divided by 1000.","solution":"936"} +{"question":"A jar has 10 red candies and 10 blue candies. Terry picks two candies at random, then Mary picks two of the remaining candies at random. Given that the probability that they get the same color combination, irrespective of order, is $m\/n,$ where $m$ and $n$ are relatively prime positive integers, find $m+n.$","solution":"441"} +{"question":"There is a unique positive real number $x$ such that the three numbers $\\log_8(2x),\\log_4x,$ and $\\log_2x,$ in that order, form a geometric progression with positive common ratio. The number $x$ can be written as $\\tfrac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$","solution":"17"} +{"question":"The members of a distinguished committee were choosing a president, and each member gave one vote to one of the $27$ candidates. For each candidate, the exact percentage of votes the candidate got was smaller by at least $1$ than the number of votes for that candidate. What is the smallest possible number of members of the committee?","solution":"134"} +{"question":"A cylindrical log has diameter $12$ inches. A wedge is cut from the log by making two planar cuts that go entirely through the log. The first is perpendicular to the axis of the cylinder, and the plane of the second cut forms a $45^\\circ$ angle with the plane of the first cut. The intersection of these two planes has exactly one point in common with the log. The number of cubic inches in the wedge can be expressed as $n\\pi$ , where n is a positive integer. Find $n$ .","solution":"216"} +{"question":"Let $a > 1$ and $x > 1$ satisfy $\\log_a(\\log_a(\\log_a 2) + \\log_a 24 - 128) = 128$ and $\\log_a(\\log_a x) = 256$ . Find the remainder when $x$ is divided by $1000$ .","solution":"896"} +{"question":"Let $x_1$ , $x_2$ , $\\dots$ , $x_6$ be nonnegative real numbers such that $x_1 + x_2 + x_3 + x_4 + x_5 + x_6 = 1$ , and $x_1x_3x_5 + x_2x_4x_6 \\ge {\\frac{1}{540}}$ . Let $p$ and $q$ be relatively prime positive integers such that $\\frac{p}{q}$ is the maximum possible value of $x_1x_2x_3 + x_2x_3x_4 + x_3x_4x_5 + x_4x_5x_6 + x_5x_6x_1 + x_6x_1x_2$ . Find $p + q$ .","solution":"559"} +{"question":"Let $\\triangle{PQR}$ be a right triangle with $PQ = 90$ , $PR = 120$ , and $QR = 150$ . Let $C_{1}$ be the inscribed circle. Construct $\\overline{ST}$ with $S$ on $\\overline{PR}$ and $T$ on $\\overline{QR}$ , such that $\\overline{ST}$ is perpendicular to $\\overline{PR}$ and tangent to $C_{1}$ . Construct $\\overline{UV}$ with $U$ on $\\overline{PQ}$ and $V$ on $\\overline{QR}$ such that $\\overline{UV}$ is perpendicular to $\\overline{PQ}$ and tangent to $C_{1}$ . Let $C_{2}$ be the inscribed circle of $\\triangle{RST}$ and $C_{3}$ the inscribed circle of $\\triangle{QUV}$ . The distance between the centers of $C_{2}$ and $C_{3}$ can be written as $\\sqrt {10n}$ . What is $n$ ?","solution":"725"} +{"question":"Let $S^{}_{}$ be the set of all rational numbers $r^{}_{}$ , $0^{}_{}1$ . Find the remainder when the smallest possible sum $m+n$ is divided by $1000$ .","solution":"371"} +{"question":"There are nonzero integers $a$ , $b$ , $r$ , and $s$ such that the complex number $r+si$ is a zero of the polynomial $P(x)={x}^{3}-a{x}^{2}+bx-65$ . For each possible combination of $a$ and $b$ , let ${p}_{a,b}$ be the sum of the zeros of $P(x)$ . Find the sum of the ${p}_{a,b}$ 's for all possible combinations of $a$ and $b$ .","solution":"80"} +{"question":"Twenty distinct points are marked on a circle and labeled $1$ through $20$ in clockwise order. A line segment is drawn between every pair of points whose labels differ by a prime number. Find the number of triangles formed whose vertices are among the original $20$ points.","solution":"72"} +{"question":"Let $f(x)$ be a third-degree polynomial with real coefficients satisfying \\[|f(1)|=|f(2)|=|f(3)|=|f(5)|=|f(6)|=|f(7)|=12.\\] Find $|f(0)|$ .","solution":"72"} +{"question":"Rectangle $ABCD$ is given with $AB=63$ and $BC=448.$ Points $E$ and $F$ lie on $AD$ and $BC$ respectively, such that $AE=CF=84.$ The inscribed circle of triangle $BEF$ is tangent to $EF$ at point $P,$ and the inscribed circle of triangle $DEF$ is tangent to $EF$ at point $Q.$ Find $PQ.$","solution":"259"} +{"question":"Hexagon $ABCDEF$ is divided into five rhombuses, $P, Q, R, S,$ and $T$ , as shown. Rhombuses $P, Q, R,$ and $S$ are congruent, and each has area $\\sqrt{2006}.$ Let $K$ be the area of rhombus $T$ . Given that $K$ is a positive integer, find the number of possible values for $K.$ [asy] \/\/ TheMathGuyd size(8cm); pair A=(0,0), B=(4.2,0), C=(5.85,-1.6), D=(4.2,-3.2), EE=(0,-3.2), F=(-1.65,-1.6), G=(0.45,-1.6), H=(3.75,-1.6), I=(2.1,0), J=(2.1,-3.2), K=(2.1,-1.6); draw(A--B--C--D--EE--F--cycle); draw(F--G--(2.1,0)); draw(C--H--(2.1,0)); draw(G--(2.1,-3.2)); draw(H--(2.1,-3.2)); label(\"$\\mathcal{T}$\",(2.1,-1.6)); label(\"$\\mathcal{P}$\",(0,-1),NE); label(\"$\\mathcal{Q}$\",(4.2,-1),NW); label(\"$\\mathcal{R}$\",(0,-2.2),SE); label(\"$\\mathcal{S}$\",(4.2,-2.2),SW); [\/asy]","solution":"89"} +{"question":"The equation $2^{333x-2} + 2^{111x+2} = 2^{222x+1} + 1$ has three real roots. Given that their sum is $\\frac mn$ where $m$ and $n$ are relatively prime positive integers, find $m+n.$","solution":"113"} +{"question":"Suppose that the measurement of time during the day is converted to the metric system so that each day has $10$ metric hours, and each metric hour has $100$ metric minutes. Digital clocks would then be produced that would read $\\text{9:99}$ just before midnight, $\\text{0:00}$ at midnight, $\\text{1:25}$ at the former $\\text{3:00}$ AM, and $\\text{7:50}$ at the former $\\text{6:00}$ PM. After the conversion, a person who wanted to wake up at the equivalent of the former $\\text{6:36}$ AM would set his new digital alarm clock for $\\text{A:BC}$ , where $\\text{A}$ , $\\text{B}$ , and $\\text{C}$ are digits. Find $100\\text{A}+10\\text{B}+\\text{C}$ .","solution":"275"} +{"question":"Let $ABCD$ be an isosceles trapezoid with $AD=BC$ and $AB1$ . Find $b$ .","solution":"216"} +{"question":"In the diagram below, angle $ABC$ is a right angle. Point $D$ is on $\\overline{BC}$ , and $\\overline{AD}$ bisects angle $CAB$ . Points $E$ and $F$ are on $\\overline{AB}$ and $\\overline{AC}$ , respectively, so that $AE=3$ and $AF=10$ . Given that $EB=9$ and $FC=27$ , find the integer closest to the area of quadrilateral $DCFG$ . [asy] size(250); pair A=(0,12), E=(0,8), B=origin, C=(24*sqrt(2),0), D=(6*sqrt(2),0), F=A+10*dir(A--C), G=intersectionpoint(E--F, A--D); draw(A--B--C--A--D^^E--F); pair point=G+1*dir(250); label(\"$A$\", A, dir(point--A)); label(\"$B$\", B, dir(point--B)); label(\"$C$\", C, dir(point--C)); label(\"$D$\", D, dir(point--D)); label(\"$E$\", E, dir(point--E)); label(\"$F$\", F, dir(point--F)); label(\"$G$\", G, dir(point--G)); markscalefactor=0.1; draw(rightanglemark(A,B,C)); label(\"10\", A--F, dir(90)*dir(A--F)); label(\"27\", F--C, dir(90)*dir(F--C)); label(\"3\", (0,10), W); label(\"9\", (0,4), W); [\/asy]","solution":"148"} +{"question":"Circle $C_0$ has radius $1$ , and the point $A_0$ is a point on the circle. Circle $C_1$ has radius $r<1$ and is internally tangent to $C_0$ at point $A_0$ . Point $A_1$ lies on circle $C_1$ so that $A_1$ is located $90^{\\circ}$ counterclockwise from $A_0$ on $C_1$ . Circle $C_2$ has radius $r^2$ and is internally tangent to $C_1$ at point $A_1$ . In this way a sequence of circles $C_1,C_2,C_3,\\ldots$ and a sequence of points on the circles $A_1,A_2,A_3,\\ldots$ are constructed, where circle $C_n$ has radius $r^n$ and is internally tangent to circle $C_{n-1}$ at point $A_{n-1}$ , and point $A_n$ lies on $C_n$ $90^{\\circ}$ counterclockwise from point $A_{n-1}$ , as shown in the figure below. There is one point $B$ inside all of these circles. When $r = \\frac{11}{60}$ , the distance from the center $C_0$ to $B$ is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ . [asy] draw(Circle((0,0),125)); draw(Circle((25,0),100)); draw(Circle((25,20),80)); draw(Circle((9,20),64)); dot((125,0)); label(\"$A_0$\",(125,0),E); dot((25,100)); label(\"$A_1$\",(25,100),SE); dot((-55,20)); label(\"$A_2$\",(-55,20),E); [\/asy]","solution":"110"} +{"question":"Jon and Steve ride their bicycles along a path that parallels two side-by-side train tracks running the east\/west direction. Jon rides east at $20$ miles per hour, and Steve rides west at $20$ miles per hour. Two trains of equal length, traveling in opposite directions at constant but different speeds each pass the two riders. Each train takes exactly $1$ minute to go past Jon. The westbound train takes $10$ times as long as the eastbound train to go past Steve. The length of each train is $\\tfrac{m}{n}$ miles, where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"49"} +{"question":"The increasing sequence $3, 15, 24, 48, \\ldots\\,$ consists of those positive multiples of 3 that are one less than a perfect square. What is the remainder when the 1994th term of the sequence is divided by 1000?","solution":"63"} +{"question":"Let $n^{}_{}$ be the smallest positive integer that is a multiple of $75_{}^{}$ and has exactly $75_{}^{}$ positive integral divisors, including $1_{}^{}$ and itself. Find $\\frac{n}{75}$ .","solution":"432"} +{"question":"In $\\triangle ABC, AB = AC = 10$ and $BC = 12$ . Point $D$ lies strictly between $A$ and $B$ on $\\overline{AB}$ and point $E$ lies strictly between $A$ and $C$ on $\\overline{AC}$ so that $AD = DE = EC$ . Then $AD$ can be expressed in the form $\\dfrac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"289"} +{"question":"The sequence $(a_n)$ satisfies $a_1 = 1$ and $5^{(a_{n + 1} - a_n)} - 1 = \\frac {1}{n + \\frac {2}{3}}$ for $n \\geq 1$ . Let $k$ be the least integer greater than $1$ for which $a_k$ is an integer. Find $k$ .","solution":"41"} +{"question":"How many of the integers between 1 and 1000, inclusive, can be expressed as the difference of the squares of two nonnegative integers?","solution":"750"} +{"question":"Rudolph bikes at a constant rate and stops for a five-minute break at the end of every mile. Jennifer bikes at a constant rate which is three-quarters the rate that Rudolph bikes, but Jennifer takes a five-minute break at the end of every two miles. Jennifer and Rudolph begin biking at the same time and arrive at the $50$ -mile mark at exactly the same time. How many minutes has it taken them?","solution":"620"} +{"question":"The graph of the equation $9x+223y=2007$ is drawn on graph paper with each square representing one unit in each direction. How many of the $1$ by $1$ graph paper squares have interiors lying entirely below the graph and entirely in the first quadrant ?","solution":"888"} +{"question":"Find the remainder when $9 \\times 99 \\times 999 \\times \\cdots \\times \\underbrace{99\\cdots9}_{\\text{999 9's}}$ is divided by $1000$ .","solution":"109"} +{"question":"For a permutation $p = (a_1,a_2,\\ldots,a_9)$ of the digits $1,2,\\ldots,9$ , let $s(p)$ denote the sum of the three $3$ -digit numbers $a_1a_2a_3$ , $a_4a_5a_6$ , and $a_7a_8a_9$ . Let $m$ be the minimum value of $s(p)$ subject to the condition that the units digit of $s(p)$ is $0$ . Let $n$ denote the number of permutations $p$ with $s(p) = m$ . Find $|m - n|$ .","solution":"162"} +{"question":"There exist $r$ unique nonnegative integers $n_1 > n_2 > \\cdots > n_r$ and $r$ integers $a_k$ ( $1\\le k\\le r$ ) with each $a_k$ either $1$ or $- 1$ such that \\[a_13^{n_1} + a_23^{n_2} + \\cdots + a_r3^{n_r} = 2008.\\] Find $n_1 + n_2 + \\cdots + n_r$ .","solution":"21"} +{"question":"For a positive integer $n$ , let $d_n$ be the units digit of $1 + 2 + \\dots + n$ . Find the remainder when \\[\\sum_{n=1}^{2017} d_n\\] is divided by $1000$ .","solution":"69"} +{"question":"Freddy the frog is jumping around the coordinate plane searching for a river, which lies on the horizontal line $y = 24$ . A fence is located at the horizontal line $y = 0$ . On each jump Freddy randomly chooses a direction parallel to one of the coordinate axes and moves one unit in that direction. When he is at a point where $y=0$ , with equal likelihoods he chooses one of three directions where he either jumps parallel to the fence or jumps away from the fence, but he never chooses the direction that would have him cross over the fence to where $y < 0$ . Freddy starts his search at the point $(0, 21)$ and will stop once he reaches a point on the river. Find the expected number of jumps it will take Freddy to reach the river.","solution":"273"} +{"question":"Let $\\triangle ABC$ be an equilateral triangle with side length $55.$ Points $D,$ $E,$ and $F$ lie on $\\overline{BC},$ $\\overline{CA},$ and $\\overline{AB},$ respectively, with $BD = 7,$ $CE=30,$ and $AF=40.$ Point $P$ inside $\\triangle ABC$ has the property that \\[\\angle AEP = \\angle BFP = \\angle CDP.\\] Find $\\tan^2(\\angle AEP).$","solution":"75"} +{"question":"Find the integer that is closest to $1000\\sum_{n=3}^{10000}\\frac1{n^2-4}$ .","solution":"521"} +{"question":"A fair coin is to be tossed $10_{}^{}$ times. Let $i\/j^{}_{}$ , in lowest terms, be the probability that heads never occur on consecutive tosses. Find $i+j_{}^{}$ .","solution":"73"} +{"question":"Let $ABCDEF$ be an equiangular hexagon such that $AB=6, BC=8, CD=10$ , and $DE=12$ . Denote $d$ the diameter of the largest circle that fits inside the hexagon. Find $d^2$ .","solution":"147"} +{"question":"Every card in a deck has a picture of one shape - circle, square, or triangle, which is painted in one of the three colors - red, blue, or green. Furthermore, each color is applied in one of three shades - light, medium, or dark. The deck has 27 cards, with every shape-color-shade combination represented. A set of three cards from the deck is called complementary if all of the following statements are true: i. Either each of the three cards has a different shape or all three of the card have the same shape. ii. Either each of the three cards has a different color or all three of the cards have the same color. iii. Either each of the three cards has a different shade or all three of the cards have the same shade. How many different complementary three-card sets are there?","solution":"117"} +{"question":"Suppose that $\\sec x+\\tan x=\\frac{22}7$ and that $\\csc x+\\cot x=\\frac mn,$ where $\\frac mn$ is in lowest terms. Find $m+n^{}_{}.$","solution":"44"} +{"question":"Let $a_n=6^{n}+8^{n}$ . Determine the remainder on dividing $a_{83}$ by $49$ .","solution":"35"} +{"question":"In a parlor game, the magician asks one of the participants to think of a three digit number $(abc)$ where $a$ , $b$ , and $c$ represent digits in base $10$ in the order indicated. The magician then asks this person to form the numbers $(acb)$ , $(bca)$ , $(bac)$ , $(cab)$ , and $(cba)$ , to add these five numbers, and to reveal their sum, $N$ . If told the value of $N$ , the magician can identify the original number, $(abc)$ . Play the role of the magician and determine the $(abc)$ if $N= 3194$ .","solution":"358"} +{"question":"In triangle $ABC$ , $\\tan \\angle CAB = 22\/7$ , and the altitude from $A$ divides $BC$ into segments of length $3$ and $17$ . What is the area of triangle $ABC$ ?","solution":"110"} +{"question":"A group of clerks is assigned the task of sorting $1775$ files. Each clerk sorts at a constant rate of $30$ files per hour. At the end of the first hour, some of the clerks are reassigned to another task; at the end of the second hour, the same number of the remaining clerks are also reassigned to another task, and a similar assignment occurs at the end of the third hour. The group finishes the sorting in $3$ hours and $10$ minutes. Find the number of files sorted during the first one and a half hours of sorting.","solution":"945"} +{"question":"In a game of Chomp , two players alternately take bites from a 5-by-7 grid of unit squares. To take a bite, a player chooses one of the remaining squares, then removes (\"eats\") all squares in the quadrant defined by the left edge (extended upward) and the lower edge (extended rightward) of the chosen square. For example, the bite determined by the shaded square in the diagram would remove the shaded square and the four squares marked by $\\times.$ (The squares with two or more dotted edges have been removed from the original board in previous moves.) AIME 1992 Problem 12.png The object of the game is to make one's opponent take the last bite. The diagram shows one of the many subsets of the set of 35 unit squares that can occur during the game of Chomp. How many different subsets are there in all? Include the full board and empty board in your count.","solution":"792"} +{"question":"Forty teams play a tournament in which every team plays every other( $39$ different opponents) team exactly once. No ties occur, and each team has a $50 \\%$ chance of winning any game it plays. The probability that no two teams win the same number of games is $m\/n,$ where $m_{}$ and $n_{}$ are relatively prime positive integers. Find $\\log_2 n.$","solution":"742"} +{"question":"A special deck of cards contains $49$ cards, each labeled with a number from $1$ to $7$ and colored with one of seven colors. Each number-color combination appears on exactly one card. Sharon will select a set of eight cards from the deck at random. Given that she gets at least one card of each color and at least one card with each number, the probability that Sharon can discard one of her cards and $\\textit{still}$ have at least one card of each color and at least one card with each number is $\\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"13"} +{"question":"Find the least positive integer $m$ such that $m^2 - m + 11$ is a product of at least four not necessarily distinct primes.","solution":"132"} +{"question":"Let $S\\,$ be a set with six elements. In how many different ways can one select two not necessarily distinct subsets of $S\\,$ so that the union of the two subsets is $S\\,$ ? The order of selection does not matter; for example, the pair of subsets $\\{a, c\\},\\{b, c, d, e, f\\}$ represents the same selection as the pair $\\{b, c, d, e, f\\},\\{a, c\\}.$ ","solution":"365"} +{"question":"The sum of all positive integers $m$ such that $\\frac{13!}{m}$ is a perfect square can be written as $2^a3^b5^c7^d11^e13^f,$ where $a,b,c,d,e,$ and $f$ are positive integers. Find $a+b+c+d+e+f.$","solution":"12"} +{"question":"Let $x_1< x_2 < x_3$ be the three real roots of the equation $\\sqrt{2014} x^3 - 4029x^2 + 2 = 0$ . Find $x_2(x_1+x_3)$ .","solution":"2"} +{"question":"A 100 foot long moving walkway moves at a constant rate of 6 feet per second. Al steps onto the start of the walkway and stands. Bob steps onto the start of the walkway two seconds later and strolls forward along the walkway at a constant rate of 4 feet per second. Two seconds after that, Cy reaches the start of the walkway and walks briskly forward beside the walkway at a constant rate of 8 feet per second. At a certain time, one of these three persons is exactly halfway between the other two. At that time, find the distance in feet between the start of the walkway and the middle person.","solution":"52"} +{"question":"In $\\triangle ABC$ with $AB=AC,$ point $D$ lies strictly between $A$ and $C$ on side $\\overline{AC},$ and point $E$ lies strictly between $A$ and $B$ on side $\\overline{AB}$ such that $AE=ED=DB=BC.$ The degree measure of $\\angle ABC$ is $\\tfrac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$ ","solution":"547"} +{"question":"Anh read a book. On the first day she read $n$ pages in $t$ minutes, where $n$ and $t$ are positive integers. On the second day Anh read $n + 1$ pages in $t + 1$ minutes. Each day thereafter Anh read one more page than she read on the previous day, and it took her one more minute than on the previous day until she completely read the $374$ page book. It took her a total of $319$ minutes to read the book. Find $n + t$ .","solution":"53"} +{"question":"Find the value of $(52+6\\sqrt{43})^{3\/2}-(52-6\\sqrt{43})^{3\/2}$ .","solution":"828"} +{"question":"A convex polyhedron $P$ has 26 vertices, 60 edges, and 36 faces, 24 of which are triangular, and 12 of which are quadrilaterals. A space diagonal is a line segment connecting two non-adjacent vertices that do not belong to the same face. How many space diagonals does $P$ have?","solution":"241"} +{"question":"Let $z=a+bi$ be the complex number with $\\vert z \\vert = 5$ and $b > 0$ such that the distance between $(1+2i)z^3$ and $z^5$ is maximized, and let $z^4 = c+di$ . Find $c+d$ .","solution":"125"} +{"question":"Circles $\\mathcal{C}_1, \\mathcal{C}_2,$ and $\\mathcal{C}_3$ have their centers at (0,0), (12,0), and (24,0), and have radii 1, 2, and 4, respectively. Line $t_1$ is a common internal tangent to $\\mathcal{C}_1$ and $\\mathcal{C}_2$ and has a positive slope, and line $t_2$ is a common internal tangent to $\\mathcal{C}_2$ and $\\mathcal{C}_3$ and has a negative slope. Given that lines $t_1$ and $t_2$ intersect at $(x,y),$ and that $x=p-q\\sqrt{r},$ where $p, q,$ and $r$ are positive integers and $r$ is not divisible by the square of any prime, find $p+q+r.$","solution":"27"} +{"question":"On square $ABCD$ , point $E$ lies on side $AD$ and point $F$ lies on side $BC$ , so that $BE=EF=FD=30$ . Find the area of the square $ABCD$ .","solution":"810"} +{"question":"The sides of rectangle $ABCD$ have lengths $10$ and $11$ . An equilateral triangle is drawn so that no point of the triangle lies outside $ABCD$ . The maximum possible area of such a triangle can be written in the form $p\\sqrt{q}-r$ , where $p$ , $q$ , and $r$ are positive integers, and $q$ is not divisible by the square of any prime number. Find $p+q+r$ .","solution":"554"} +{"question":"Let triangle $ABC$ be a right triangle in the $xy$ -plane with a right angle at $C_{}$ . Given that the length of the hypotenuse $AB$ is $60$ , and that the medians through $A$ and $B$ lie along the lines $y=x+3$ and $y=2x+4$ respectively, find the area of triangle $ABC$ .","solution":"400"} +{"question":"Let $\\mathrm {P}$ be the product of the roots of $z^6+z^4+z^3+z^2+1=0$ that have a positive imaginary part, and suppose that $\\mathrm {P}=r(\\cos{\\theta^{\\circ}}+i\\sin{\\theta^{\\circ}})$ , where $02$ (3) $a_9=k$ are satisfied by more than one sequence.","solution":"748"} +{"question":"Consider the polynomials $P(x) = x^{6} - x^{5} - x^{3} - x^{2} - x$ and $Q(x) = x^{4} - x^{3} - x^{2} - 1.$ Given that $z_{1},z_{2},z_{3},$ and $z_{4}$ are the roots of $Q(x) = 0,$ find $P(z_{1}) + P(z_{2}) + P(z_{3}) + P(z_{4}).$","solution":"6"} +{"question":"For $1 \\leq i \\leq 215$ let $a_i = \\dfrac{1}{2^{i}}$ and $a_{216} = \\dfrac{1}{2^{215}}$ . Let $x_1, x_2, ..., x_{216}$ be positive real numbers such that $\\sum_{i=1}^{216} x_i=1$ and $\\sum_{1 \\leq i < j \\leq 216} x_ix_j = \\dfrac{107}{215} + \\sum_{i=1}^{216} \\dfrac{a_i x_i^{2}}{2(1-a_i)}$ . The maximum possible value of $x_2=\\dfrac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"863"} +{"question":"Find the number of ways $66$ identical coins can be separated into three nonempty piles so that there are fewer coins in the first pile than in the second pile and fewer coins in the second pile than in the third pile.","solution":"331"} +{"question":"Three concentric circles have radii $3,$ $4,$ and $5.$ An equilateral triangle with one vertex on each circle has side length $s.$ The largest possible area of the triangle can be written as $a + \\tfrac{b}{c} \\sqrt{d},$ where $a,$ $b,$ $c,$ and $d$ are positive integers, $b$ and $c$ are relatively prime, and $d$ is not divisible by the square of any prime. Find $a+b+c+d.$","solution":"41"} +{"question":"Four circles $\\omega,$ $\\omega_{A},$ $\\omega_{B},$ and $\\omega_{C}$ with the same radius are drawn in the interior of triangle $ABC$ such that $\\omega_{A}$ is tangent to sides $AB$ and $AC$ , $\\omega_{B}$ to $BC$ and $BA$ , $\\omega_{C}$ to $CA$ and $CB$ , and $\\omega$ is externally tangent to $\\omega_{A},$ $\\omega_{B},$ and $\\omega_{C}$ . If the sides of triangle $ABC$ are $13,$ $14,$ and $15,$ the radius of $\\omega$ can be represented in the form $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n.$","solution":"389"} +{"question":"Let $m$ be the number of solutions in positive integers to the equation $4x+3y+2z=2009$ , and let $n$ be the number of solutions in positive integers to the equation $4x+3y+2z=2000$ . Find the remainder when $m-n$ is divided by $1000$ .","solution":"0"} +{"question":"Let $N$ be the number of positive integers that are less than or equal to 2003 and whose base-2 representation has more 1's than 0's. Find the remainder when $N$ is divided by 1000.","solution":"155"} +{"question":"The function $f$ defined by $f(x)= \\frac{ax+b}{cx+d}$ , where $a$ , $b$ , $c$ and $d$ are nonzero real numbers, has the properties $f(19)=19$ , $f(97)=97$ and $f(f(x))=x$ for all values except $\\frac{-d}{c}$ . Find the unique number that is not in the range of $f$ .","solution":"58"} +{"question":"In $\\triangle ABC$ , $AB=10$ , $\\measuredangle A=30^{\\circ}$ , and $\\measuredangle C=45^{\\circ}$ . Let $H$ , $D$ , and $M$ be points on line $\\overline{BC}$ such that $AH\\perp BC$ , $\\measuredangle BAD=\\measuredangle CAD$ , and $BM=CM$ . Point $N$ is the midpoint of segment $HM$ , and point $P$ is on ray $AD$ such that $PN\\perp BC$ . Then $AP^2=\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"77"} +{"question":"A mathematical organization is producing a set of commemorative license plates. Each plate contains a sequence of five characters chosen from the four letters in AIME and the four digits in $2007$ . No character may appear in a sequence more times than it appears among the four letters in AIME or the four digits in $2007$ . A set of plates in which each possible sequence appears exactly once contains N license plates. Find N\/10.","solution":"372"} +{"question":"How many integers $N$ less than 1000 can be written as the sum of $j$ consecutive positive odd integers from exactly 5 values of $j\\ge 1$ ?","solution":"15"} +{"question":"Assume that $x_1,x_2,\\ldots,x_7$ are real numbers such that \\begin{align*} x_1 + 4x_2 + 9x_3 + 16x_4 + 25x_5 + 36x_6 + 49x_7 &= 1, \\\\ 4x_1 + 9x_2 + 16x_3 + 25x_4 + 36x_5 + 49x_6 + 64x_7 &= 12, \\\\ 9x_1 + 16x_2 + 25x_3 + 36x_4 + 49x_5 + 64x_6 + 81x_7 &= 123. \\end{align*} Find the value of $16x_1+25x_2+36x_3+49x_4+64x_5+81x_6+100x_7$ .","solution":"334"} +{"question":"Triangle $ABC$ has positive integer side lengths with $AB=AC$ . Let $I$ be the intersection of the bisectors of $\\angle B$ and $\\angle C$ . Suppose $BI=8$ . Find the smallest possible perimeter of $\\triangle ABC$ .","solution":"108"} +{"question":"In $\\triangle ABC$ , $AC = BC$ , and point $D$ is on $\\overline{BC}$ so that $CD = 3\\cdot BD$ . Let $E$ be the midpoint of $\\overline{AD}$ . Given that $CE = \\sqrt{7}$ and $BE = 3$ , the area of $\\triangle ABC$ can be expressed in the form $m\\sqrt{n}$ , where $m$ and $n$ are positive integers and $n$ is not divisible by the square of any prime. Find $m+n$ .","solution":"10"} +{"question":"A certain function $f$ has the properties that $f(3x) = 3f(x)$ for all positive real values of $x$ , and that $f(x) = 1 - |x - 2|$ for $1\\leq x \\leq 3$ . Find the smallest $x$ for which $f(x) = f(2001)$ .","solution":"429"} +{"question":"The coordinates of the vertices of isosceles trapezoid $ABCD$ are all integers, with $A=(20,100)$ and $D=(21,107)$ . The trapezoid has no horizontal or vertical sides, and $\\overline{AB}$ and $\\overline{CD}$ are the only parallel sides. The sum of the absolute values of all possible slopes for $\\overline{AB}$ is $m\/n$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"131"} +{"question":"An angle $x$ is chosen at random from the interval $0^\\circ < x < 90^\\circ.$ Let $p$ be the probability that the numbers $\\sin^2 x, \\cos^2 x,$ and $\\sin x \\cos x$ are not the lengths of the sides of a triangle. Given that $p = d\/n,$ where $d$ is the number of degrees in $\\arctan m$ and $m$ and $n$ are positive integers with $m + n < 1000,$ find $m + n.$","solution":"92"} +{"question":"Club Truncator is in a soccer league with six other teams, each of which it plays once. In any of its 6 matches, the probabilities that Club Truncator will win, lose, or tie are each $\\frac {1}{3}$ . The probability that Club Truncator will finish the season with more wins than losses is $\\frac {m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"341"} +{"question":"The polynomial $P(x)$ is cubic. What is the largest value of $k$ for which the polynomials $Q_1(x) = x^2 + (k-29)x - k$ and $Q_2(x) = 2x^2+ (2k-43)x + k$ are both factors of $P(x)$ ?","solution":"30"} +{"question":"Let $P$ be the product of the first 100 positive odd integers. Find the largest integer $k$ such that $P$ is divisible by $3^k$ .","solution":"49"} +{"question":"The director of a marching band wishes to place the members into a formation that includes all of them and has no unfilled positions. If they are arranged in a square formation, there are 5 members left over. The director realizes that if he arranges the group in a formation with 7 more rows than columns, there are no members left over. Find the maximum number of members this band can have.","solution":"294"} +{"question":"Let $ABCD$ be a convex quadrilateral with $AB=2, AD=7,$ and $CD=3$ such that the bisectors of acute angles $\\angle{DAB}$ and $\\angle{ADC}$ intersect at the midpoint of $\\overline{BC}.$ Find the square of the area of $ABCD.$","solution":"180"} +{"question":"Let $ABCDEF$ be a regular hexagon. Let $G$ , $H$ , $I$ , $J$ , $K$ , and $L$ be the midpoints of sides $AB$ , $BC$ , $CD$ , $DE$ , $EF$ , and $AF$ , respectively. The segments $\\overline{AH}$ , $\\overline{BI}$ , $\\overline{CJ}$ , $\\overline{DK}$ , $\\overline{EL}$ , and $\\overline{FG}$ bound a smaller regular hexagon. Let the ratio of the area of the smaller hexagon to the area of $ABCDEF$ be expressed as a fraction $\\frac {m}{n}$ where $m$ and $n$ are relatively prime positive integers. Find $m + n$ . ","solution":"11"} +{"question":"A machine-shop cutting tool has the shape of a notched circle, as shown. The radius of the circle is $\\sqrt{50}$ cm, the length of $AB$ is $6$ cm and that of $BC$ is $2$ cm. The angle $ABC$ is a right angle. Find the square of the distance (in centimeters) from $B$ to the center of the circle. [asy] size(150); defaultpen(linewidth(0.6)+fontsize(11)); real r=10; pair O=(0,0), A=r*dir(45),B=(A.x,A.y-r); path P=circle(O,r); pair C=intersectionpoint(B--(B.x+r,B.y),P); \/\/ Drawing arc instead of full circle \/\/draw(P); draw(arc(O, r, degrees(A), degrees(C))); draw(C--B--A--B); dot(A); dot(B); dot(C); label(\"$A$\",A,NE); label(\"$B$\",B,S); label(\"$C$\",C,SE); [\/asy]","solution":"26"} +{"question":"A frog is positioned at the origin of the coordinate plane. From the point $(x, y)$ , the frog can jump to any of the points $(x + 1, y)$ , $(x + 2, y)$ , $(x, y + 1)$ , or $(x, y + 2)$ . Find the number of distinct sequences of jumps in which the frog begins at $(0, 0)$ and ends at $(4, 4)$ .","solution":"556"} +{"question":"In a group of nine people each person shakes hands with exactly two of the other people from the group. Let $N$ be the number of ways this handshaking can occur. Consider two handshaking arrangements different if and only if at least two people who shake hands under one arrangement do not shake hands under the other arrangement. Find the remainder when $N$ is divided by $1000$ .","solution":"16"} +{"question":"The integer $n$ is the smallest positive multiple of $15$ such that every digit of $n$ is either $8$ or $0$ . Compute $\\frac{n}{15}$ .","solution":"592"} +{"question":"In right triangle $ABC$ with right angle $C$ , $CA = 30$ and $CB = 16$ . Its legs $CA$ and $CB$ are extended beyond $A$ and $B$ . Points $O_1$ and $O_2$ lie in the exterior of the triangle and are the centers of two circles with equal radii. The circle with center $O_1$ is tangent to the hypotenuse and to the extension of leg $CA$ , the circle with center $O_2$ is tangent to the hypotenuse and to the extension of leg $CB$ , and the circles are externally tangent to each other. The length of the radius of either circle can be expressed as $p\/q$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"737"} +{"question":"In $\\triangle ABC$ with side lengths $AB = 13,$ $BC = 14,$ and $CA = 15,$ let $M$ be the midpoint of $\\overline{BC}.$ Let $P$ be the point on the circumcircle of $\\triangle ABC$ such that $M$ is on $\\overline{AP}.$ There exists a unique point $Q$ on segment $\\overline{AM}$ such that $\\angle PBQ = \\angle PCQ.$ Then $AQ$ can be written as $\\frac{m}{\\sqrt{n}},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$","solution":"247"} +{"question":"Ed and Sue bike at equal and constant rates. Similarly, they jog at equal and constant rates, and they swim at equal and constant rates. Ed covers $74$ kilometers after biking for $2$ hours, jogging for $3$ hours, and swimming for $4$ hours, while Sue covers $91$ kilometers after jogging for $2$ hours, swimming for $3$ hours, and biking for $4$ hours. Their biking, jogging, and swimming rates are all whole numbers of kilometers per hour. Find the sum of the squares of Ed's biking, jogging, and swimming rates.","solution":"314"} +{"question":"There is a positive real number $x$ not equal to either $\\tfrac{1}{20}$ or $\\tfrac{1}{2}$ such that \\[\\log_{20x} (22x)=\\log_{2x} (202x).\\] The value $\\log_{20x} (22x)$ can be written as $\\log_{10} (\\tfrac{m}{n})$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"112"} +{"question":"The complex number $z$ is equal to $9+bi$ , where $b$ is a positive real number and $i^{2}=-1$ . Given that the imaginary parts of $z^{2}$ and $z^{3}$ are the same, what is $b$ equal to?","solution":"15"} +{"question":"There are $2^{10} = 1024$ possible $10$ -letter strings in which each letter is either an A or a B. Find the number of such strings that do not have more than $3$ adjacent letters that are identical.","solution":"548"} +{"question":"Someone observed that $6! = 8 \\cdot 9 \\cdot 10$ . Find the largest positive integer $n^{}_{}$ for which $n^{}_{}!$ can be expressed as the product of $n - 3_{}^{}$ consecutive positive integers.","solution":"23"} +{"question":"Triangle $ABC$ with right angle at $C$ , $\\angle BAC < 45^\\circ$ and $AB = 4$ . Point $P$ on $\\overline{AB}$ is chosen such that $\\angle APC = 2\\angle ACP$ and $CP = 1$ . The ratio $\\frac{AP}{BP}$ can be represented in the form $p + q\\sqrt{r}$ , where $p$ , $q$ , $r$ are positive integers and $r$ is not divisible by the square of any prime. Find $p+q+r$ .","solution":"7"} +{"question":"A function $f$ is defined on the complex numbers by $f(z)=(a+bi)z,$ where $a_{}$ and $b_{}$ are positive numbers. This function has the property that the image of each point in the complex plane is equidistant from that point and the origin. Given that $|a+bi|=8$ and that $b^2=m\/n,$ where $m_{}$ and $n_{}$ are relatively prime positive integers. Find $m+n.$","solution":"259"} +{"question":"The numbers 1, 2, 3, 4, 5, 6, 7, and 8 are randomly written on the faces of a regular octahedron so that each face contains a different number. The probability that no two consecutive numbers, where 8 and 1 are considered to be consecutive, are written on faces that share an edge is $m\/n,$ where $m$ and $n$ are relatively prime positive integers. Find $m + n.$","solution":"85"} +{"question":"Call a positive integer $n$ $k$ - pretty if $n$ has exactly $k$ positive divisors and $n$ is divisible by $k$ . For example, $18$ is $6$ -pretty. Let $S$ be the sum of the positive integers less than $2019$ that are $20$ -pretty. Find $\\tfrac{S}{20}$ .","solution":"472"} +{"question":"Given that $O$ is a regular octahedron, that $C$ is the cube whose vertices are the centers of the faces of $O,$ and that the ratio of the volume of $O$ to that of $C$ is $\\frac mn,$ where $m$ and $n$ are relatively prime integers, find $m+n.$ ","solution":"11"} +{"question":"The nine delegates to the Economic Cooperation Conference include $2$ officials from Mexico, $3$ officials from Canada, and $4$ officials from the United States. During the opening session, three of the delegates fall asleep. Assuming that the three sleepers were determined randomly, the probability that exactly two of the sleepers are from the same country is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"139"} +{"question":"Triangle $ABC$ has side lengths $AB=7,BC=8,$ and $CA=9.$ Circle $\\omega_1$ passes through $B$ and is tangent to line $AC$ at $A.$ Circle $\\omega_2$ passes through $C$ and is tangent to line $AB$ at $A.$ Let $K$ be the intersection of circles $\\omega_1$ and $\\omega_2$ not equal to $A.$ Then $AK=\\tfrac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$","solution":"11"} +{"question":"The points $(0,0)\\,$ , $(a,11)\\,$ , and $(b,37)\\,$ are the vertices of an equilateral triangle. Find the value of $ab\\,$ .","solution":"315"} +{"question":"Determine the number of ordered pairs $(a,b)$ of integers such that $\\log_a b + 6\\log_b a=5, 2 \\leq a \\leq 2005,$ and $2 \\leq b \\leq 2005.$","solution":"54"} +{"question":"Find $x^2+y^2_{}$ if $x_{}^{}$ and $y_{}^{}$ are positive integers such that \\begin{align*} xy+x+y&=71, \\\\ x^2y+xy^2&=880. \\end{align*}","solution":"146"} +{"question":"In triangle $ABC$ , point $D$ is on $\\overline{BC}$ with $CD=2$ and $DB=5$ , point $E$ is on $\\overline{AC}$ with $CE=1$ and $EA=3$ , $AB=8$ , and $\\overline{AD}$ and $\\overline{BE}$ intersect at $P$ . Points $Q$ and $R$ lie on $\\overline{AB}$ so that $\\overline{PQ}$ is parallel to $\\overline{CA}$ and $\\overline{PR}$ is parallel to $\\overline{CB}$ . It is given that the ratio of the area of triangle $PQR$ to the area of triangle $ABC$ is $m\/n$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"901"} +{"question":"Trapezoid $ABCD^{}_{}$ has sides $AB=92^{}_{}$ , $BC=50^{}_{}$ , $CD=19^{}_{}$ , and $AD=70^{}_{}$ , with $AB^{}_{}$ parallel to $CD^{}_{}$ . A circle with center $P^{}_{}$ on $AB^{}_{}$ is drawn tangent to $BC^{}_{}$ and $AD^{}_{}$ . Given that $AP^{}_{}=\\frac mn$ , where $m^{}_{}$ and $n^{}_{}$ are relatively prime positive integers, find $m+n^{}_{}$ .","solution":"164"} +{"question":"What is the product of the real roots of the equation $x^2 + 18x + 30 = 2 \\sqrt{x^2 + 18x + 45}$ ?","solution":"20"} +{"question":"Call a $3$ -digit number geometric if it has $3$ distinct digits which, when read from left to right, form a geometric sequence. Find the difference between the largest and smallest geometric numbers.","solution":"840"} +{"question":"Let $a,b,c,d,e,f,g,h,i$ be distinct integers from $1$ to $9.$ The minimum possible positive value of \\[\\dfrac{a \\cdot b \\cdot c - d \\cdot e \\cdot f}{g \\cdot h \\cdot i}\\] can be written as $\\frac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$","solution":"289"} +{"question":"The sequence $a_1, a_2, \\ldots$ is geometric with $a_1=a$ and common ratio $r,$ where $a$ and $r$ are positive integers. Given that $\\log_8 a_1+\\log_8 a_2+\\cdots+\\log_8 a_{12} = 2006,$ find the number of possible ordered pairs $(a,r).$","solution":"46"} +{"question":"The vertices of a regular nonagon (9-sided polygon) are to be labeled with the digits 1 through 9 in such a way that the sum of the numbers on every three consecutive vertices is a multiple of 3. Two acceptable arrangements are considered to be indistinguishable if one can be obtained from the other by rotating the nonagon in the plane. Find the number of distinguishable acceptable arrangements.","solution":"144"} +{"question":"Let $m$ be the number of five-element subsets that can be chosen from the set of the first $14$ natural numbers so that at least two of the five numbers are consecutive. Find the remainder when $m$ is divided by $1000$ .","solution":"750"} +{"question":"The sum of the first $2011$ terms of a geometric sequence is $200$ . The sum of the first $4022$ terms is $380$ . Find the sum of the first $6033$ terms.","solution":"542"} +{"question":"Let $S$ be the sum of the base $10$ logarithms of all the proper divisors of $1000000$ . What is the integer nearest to $S$ ?","solution":"141"} +{"question":"In quadrilateral $ABCD, BC=8, CD=12, AD=10,$ and $m\\angle A= m\\angle B = 60^\\circ.$ Given that $AB = p + \\sqrt{q},$ where $p$ and $q$ are positive integers, find $p+q.$","solution":"150"} +{"question":"A rectangular box has width $12$ inches, length $16$ inches, and height $\\frac{m}{n}$ inches, where $m$ and $n$ are relatively prime positive integers. Three faces of the box meet at a corner of the box. The center points of those three faces are the vertices of a triangle with an area of $30$ square inches. Find $m+n$ .","solution":"41"} +{"question":"Suppose that $y = \\frac34x$ and $x^y = y^x$ . The quantity $x + y$ can be expressed as a rational number $\\frac {r}{s}$ , where $r$ and $s$ are relatively prime positive integers. Find $r + s$ .","solution":"529"} +{"question":"Let $SP_1P_2P_3EP_4P_5$ be a heptagon. A frog starts jumping at vertex $S$ . From any vertex of the heptagon except $E$ , the frog may jump to either of the two adjacent vertices. When it reaches vertex $E$ , the frog stops and stays there. Find the number of distinct sequences of jumps of no more than $12$ jumps that end at $E$ .","solution":"351"} +{"question":"The pages of a book are numbered $1_{}^{}$ through $n_{}^{}$ . When the page numbers of the book were added, one of the page numbers was mistakenly added twice, resulting in an incorrect sum of $1986_{}^{}$ . What was the number of the page that was added twice?","solution":"33"} +{"question":"Adults made up $\\frac5{12}$ of the crowd of people at a concert. After a bus carrying $50$ more people arrived, adults made up $\\frac{11}{25}$ of the people at the concert. Find the minimum number of adults who could have been at the concert after the bus arrived.","solution":"154"} +{"question":"Three circles, each of radius $3$ , are drawn with centers at $(14, 92)$ , $(17, 76)$ , and $(19, 84)$ . A line passing through $(17,76)$ is such that the total area of the parts of the three circles to one side of the line is equal to the total area of the parts of the three circles to the other side of it. What is the absolute value of the slope of this line?","solution":"24"} +{"question":"The $52$ cards in a deck are numbered $1, 2, \\cdots, 52$ . Alex, Blair, Corey, and Dylan each pick a card from the deck randomly and without replacement. The two people with lower numbered cards form a team, and the two people with higher numbered cards form another team. Let $p(a)$ be the probability that Alex and Dylan are on the same team, given that Alex picks one of the cards $a$ and $a+9$ , and Dylan picks the other of these two cards. The minimum value of $p(a)$ for which $p(a)\\ge\\frac{1}{2}$ can be written as $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"263"} +{"question":"Let the sum of a set of numbers be the sum of its elements. Let $S$ be a set of positive integers, none greater than 15. Suppose no two disjoint subsets of $S$ have the same sum. What is the largest sum a set $S$ with these properties can have?","solution":"61"} +{"question":"A right square pyramid with volume $54$ has a base with side length $6.$ The five vertices of the pyramid all lie on a sphere with radius $\\frac mn$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"21"} +{"question":"Charles has two six-sided dice. One of the die is fair, and the other die is biased so that it comes up six with probability $\\frac{2}{3}$ and each of the other five sides has probability $\\frac{1}{15}$ . Charles chooses one of the two dice at random and rolls it three times. Given that the first two rolls are both sixes, the probability that the third roll will also be a six is $\\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"167"} +{"question":"Find the number of permutations of $1, 2, 3, 4, 5, 6$ such that for each $k$ with $1$ $\\leq$ $k$ $\\leq$ $5$ , at least one of the first $k$ terms of the permutation is greater than $k$ .","solution":"461"} +{"question":"An equilateral triangle is inscribed in the ellipse whose equation is $x^2+4y^2=4$ . One vertex of the triangle is $(0,1)$ , one altitude is contained in the y-axis, and the length of each side is $\\sqrt{\\frac mn}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"937"} +{"question":"Five towns are connected by a system of roads. There is exactly one road connecting each pair of towns. Find the number of ways there are to make all the roads one-way in such a way that it is still possible to get from any town to any other town using the roads (possibly passing through other towns on the way). ","solution":"544"} +{"question":"Circles of radius $3$ and $6$ are externally tangent to each other and are internally tangent to a circle of radius $9$ . The circle of radius $9$ has a chord that is a common external tangent of the other two circles. Find the square of the length of this chord.","solution":"224"} +{"question":"If the integer $k^{}_{}$ is added to each of the numbers $36^{}_{}$ , $300^{}_{}$ , and $596^{}_{}$ , one obtains the squares of three consecutive terms of an arithmetic series. Find $k^{}_{}$ .","solution":"925"} +{"question":"Three spheres with radii $11,$ $13,$ and $19$ are mutually externally tangent. A plane intersects the spheres in three congruent circles centered at $A,$ $B,$ and $C,$ respectively, and the centers of the spheres all lie on the same side of this plane. Suppose that $AB^2 = 560.$ Find $AC^2.$","solution":"756"} +{"question":"A right rectangular prism $P_{}$ (i.e., a rectangular parallelepiped) has sides of integral length $a, b, c,$ with $a\\le b\\le c.$ A plane parallel to one of the faces of $P_{}$ cuts $P_{}$ into two prisms, one of which is similar to $P_{},$ and both of which have nonzero volume. Given that $b=1995,$ for how many ordered triples $(a, b, c)$ does such a plane exist?","solution":"40"} +{"question":"Find the minimum value of $\\frac{9x^2\\sin^2 x + 4}{x\\sin x}$ for $0 < x < \\pi$ .","solution":"12"} +{"question":"The function f is defined on the set of integers and satisfies $f(n)= \\begin{cases} n-3 & \\mbox{if }n\\ge 1000 \\\\ f(f(n+5)) & \\mbox{if }n<1000 \\end{cases}$ Find $f(84)$ .","solution":"997"} +{"question":"Triangle $ABC$ is isosceles with $AC = BC$ and $\\angle ACB = 106^\\circ.$ Point $M$ is in the interior of the triangle so that $\\angle MAC = 7^\\circ$ and $\\angle MCA = 23^\\circ.$ Find the number of degrees in $\\angle CMB.$","solution":"83"} +{"question":"Positive real numbers $b \\not= 1$ and $n$ satisfy the equations \\[\\sqrt{\\log_b n} = \\log_b \\sqrt{n} \\qquad \\text{and} \\qquad b \\cdot \\log_b n = \\log_b (bn).\\] The value of $n$ is $\\frac{j}{k},$ where $j$ and $k$ are relatively prime positive integers. Find $j+k.$","solution":"881"} +{"question":"A square pyramid with base $ABCD$ and vertex $E$ has eight edges of length 4. A plane passes through the midpoints of $AE$ , $BC$ , and $CD$ . The plane's intersection with the pyramid has an area that can be expressed as $\\sqrt{p}$ . Find $p$ .","solution":"80"} +{"question":"Two mathematicians take a morning coffee break each day. They arrive at the cafeteria independently, at random times between 9 a.m. and 10 a.m., and stay for exactly $m$ minutes. The probability that either one arrives while the other is in the cafeteria is $40 \\%,$ and $m = a - b\\sqrt {c},$ where $a, b,$ and $c$ are positive integers , and $c$ is not divisible by the square of any prime . Find $a + b + c.$","solution":"87"} +{"question":"The lengths of the sides of a triangle with positive area are $\\log_{10} 12$ , $\\log_{10} 75$ , and $\\log_{10} n$ , where $n$ is a positive integer. Find the number of possible values for $n$ .","solution":"893"} +{"question":"Let $S = \\{2^0,2^1,2^2,\\ldots,2^{10}\\}$ . Consider all possible positive differences of pairs of elements of $S$ . Let $N$ be the sum of all of these differences. Find the remainder when $N$ is divided by $1000$ .","solution":"398"} +{"question":"What is the largest positive integer $n$ for which there is a unique integer $k$ such that $\\frac{8}{15} < \\frac{n}{n + k} < \\frac{7}{13}$ ?","solution":"112"} +{"question":"What is the sum of the solutions to the equation $\\sqrt[4]{x} = \\frac{12}{7 - \\sqrt[4]{x}}$ ?","solution":"337"} +{"question":"Find the number of positive integers less than or equal to $2017$ whose base-three representation contains no digit equal to $0$ .","solution":"222"} +{"question":"A rectangle has sides of length $a$ and 36. A hinge is installed at each vertex of the rectangle, and at the midpoint of each side of length 36. The sides of length $a$ can be pressed toward each other keeping those two sides parallel so the rectangle becomes a convex hexagon as shown. When the figure is a hexagon with the sides of length $a$ parallel and separated by a distance of 24, the hexagon has the same area as the original rectangle. Find $a^2$ . [asy] pair A,B,C,D,E,F,R,S,T,X,Y,Z; dotfactor = 2; unitsize(.1cm); A = (0,0); B = (0,18); C = (0,36); \/\/ don't look here D = (12*2.236, 36); E = (12*2.236, 18); F = (12*2.236, 0); draw(A--B--C--D--E--F--cycle); dot(\" \",A,NW); dot(\" \",B,NW); dot(\" \",C,NW); dot(\" \",D,NW); dot(\" \",E,NW); dot(\" \",F,NW); \/\/don't look here R = (12*2.236 +22,0); S = (12*2.236 + 22 - 13.4164,12); T = (12*2.236 + 22,24); X = (12*4.472+ 22,24); Y = (12*4.472+ 22 + 13.4164,12); Z = (12*4.472+ 22,0); draw(R--S--T--X--Y--Z--cycle); dot(\" \",R,NW); dot(\" \",S,NW); dot(\" \",T,NW); dot(\" \",X,NW); dot(\" \",Y,NW); dot(\" \",Z,NW); \/\/ sqrt180 = 13.4164 \/\/ sqrt5 = 2.236[\/asy]","solution":"720"} +{"question":"How many ordered four-tuples of integers $(a,b,c,d)\\,$ with $0 < a < b < c < d < 500\\,$ satisfy $a + d = b + c\\,$ and $bc - ad = 93\\,$ ?","solution":"870"} +{"question":"What is the largest positive integer that is not the sum of a positive integral multiple of 42 and a positive composite integer?","solution":"215"} +{"question":"Let $f_1(x) = \\frac23 - \\frac3{3x+1}$ , and for $n \\ge 2$ , define $f_n(x) = f_1(f_{n-1}(x))$ . The value of $x$ that satisfies $f_{1001}(x) = x-3$ can be expressed in the form $\\frac mn$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"8"} +{"question":"Suppose that the angles of $\\triangle ABC$ satisfy $\\cos(3A)+\\cos(3B)+\\cos(3C)=1$ . Two sides of the triangle have lengths 10 and 13. There is a positive integer $m$ so that the maximum possible length for the remaining side of $\\triangle ABC$ is $\\sqrt{m}$ . Find $m$ .","solution":"399"} +{"question":"Let $A$ , $B$ , $C$ and $D$ be the vertices of a regular tetrahedron, each of whose edges measures $1$ meter. A bug, starting from vertex $A$ , observes the following rule: at each vertex it chooses one of the three edges meeting at that vertex, each edge being equally likely to be chosen, and crawls along that edge to the vertex at its opposite end. Let $p = \\frac{n}{729}$ be the probability that the bug is at vertex $A$ when it has crawled exactly $7$ meters. Find the value of $n$ .","solution":"182"} +{"question":"Find the smallest positive integer whose cube ends in $888$ .","solution":"192"} +{"question":"For how many values of $k$ is $12^{12}$ the least common multiple of the positive integers $6^6$ and $8^8$ , and $k$ ?","solution":"25"} +{"question":"Rhombus $PQRS^{}_{}$ is inscribed in rectangle $ABCD^{}_{}$ so that vertices $P^{}_{}$ , $Q^{}_{}$ , $R^{}_{}$ , and $S^{}_{}$ are interior points on sides $\\overline{AB}$ , $\\overline{BC}$ , $\\overline{CD}$ , and $\\overline{DA}$ , respectively. It is given that $PB^{}_{}=15$ , $BQ^{}_{}=20$ , $PR^{}_{}=30$ , and $QS^{}_{}=40$ . Let $m\/n^{}_{}$ , in lowest terms, denote the perimeter of $ABCD^{}_{}$ . Find $m+n^{}_{}$ .","solution":"677"} +{"question":"A right circular cone has a base with radius 600 and height $200\\sqrt{7}.$ A fly starts at a point on the surface of the cone whose distance from the vertex of the cone is 125, and crawls along the surface of the cone to a point on the exact opposite side of the cone whose distance from the vertex is $375\\sqrt{2}.$ Find the least distance that the fly could have crawled.","solution":"625"} +{"question":"In triangle $ABC$ , $AB=13$ , $BC=15$ and $CA=17$ . Point $D$ is on $\\overline{AB}$ , $E$ is on $\\overline{BC}$ , and $F$ is on $\\overline{CA}$ . Let $AD=p\\cdot AB$ , $BE=q\\cdot BC$ , and $CF=r\\cdot CA$ , where $p$ , $q$ , and $r$ are positive and satisfy $p+q+r=2\/3$ and $p^2+q^2+r^2=2\/5$ . The ratio of the area of triangle $DEF$ to the area of triangle $ABC$ can be written in the form $m\/n$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"61"} +{"question":"Evaluate the product \\[\\left(\\sqrt{5}+\\sqrt{6}+\\sqrt{7}\\right)\\left(\\sqrt{5}+\\sqrt{6}-\\sqrt{7}\\right)\\left(\\sqrt{5}-\\sqrt{6}+\\sqrt{7}\\right)\\left(-\\sqrt{5}+\\sqrt{6}+\\sqrt{7}\\right).\\]","solution":"104"} +{"question":"Let $w = \\dfrac{\\sqrt{3} + i}{2}$ and $z = \\dfrac{-1 + i\\sqrt{3}}{2},$ where $i = \\sqrt{-1}.$ Find the number of ordered pairs $(r,s)$ of positive integers not exceeding $100$ that satisfy the equation $i \\cdot w^r = z^s.$","solution":"834"} +{"question":"Let $w_1$ and $w_2$ denote the circles $x^2+y^2+10x-24y-87=0$ and $x^2 +y^2-10x-24y+153=0,$ respectively. Let $m$ be the smallest positive value of $a$ for which the line $y=ax$ contains the center of a circle that is externally tangent to $w_2$ and internally tangent to $w_1.$ Given that $m^2=\\frac pq,$ where $p$ and $q$ are relatively prime integers, find $p+q.$","solution":"169"} +{"question":"Let $N$ be the greatest integer multiple of $36$ all of whose digits are even and no two of whose digits are the same. Find the remainder when $N$ is divided by $1000$ .","solution":"640"} +{"question":"A coin that comes up heads with probability $p > 0$ and tails with probability $1 - p > 0$ independently on each flip is flipped eight times. Suppose the probability of three heads and five tails is equal to $\\frac {1}{25}$ of the probability of five heads and three tails. Let $p = \\frac {m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"11"} +{"question":"In the array of $13$ squares shown below, $8$ squares are colored red, and the remaining $5$ squares are colored blue. If one of all possible such colorings is chosen at random, the probability that the chosen colored array appears the same when rotated $90^{\\circ}$ around the central square is $\\frac{1}{n}$ , where $n$ is a positive integer. Find $n$ . [asy] draw((0,0)--(1,0)--(1,1)--(0,1)--(0,0)); draw((2,0)--(2,2)--(3,2)--(3,0)--(3,1)--(2,1)--(4,1)--(4,0)--(2,0)); draw((1,2)--(1,4)--(0,4)--(0,2)--(0,3)--(1,3)--(-1,3)--(-1,2)--(1,2)); draw((-1,1)--(-3,1)--(-3,0)--(-1,0)--(-2,0)--(-2,1)--(-2,-1)--(-1,-1)--(-1,1)); draw((0,-1)--(0,-3)--(1,-3)--(1,-1)--(1,-2)--(0,-2)--(2,-2)--(2,-1)--(0,-1)); size(100);[\/asy]","solution":"429"} +{"question":"A car travels due east at $\\frac 23$ miles per minute on a long, straight road. At the same time, a circular storm, whose radius is $51$ miles, moves southeast at $\\frac 12\\sqrt{2}$ miles per minute. At time $t=0$ , the center of the storm is $110$ miles due north of the car. At time $t=t_1$ minutes, the car enters the storm circle, and at time $t=t_2$ minutes, the car leaves the storm circle. Find $\\frac 12(t_1+t_2)$ .","solution":"198"} +{"question":"Ten adults enter a room, remove their shoes, and toss their shoes into a pile. Later, a child randomly pairs each left shoe with a right shoe without regard to which shoes belong together. The probability that for every positive integer $k<5$ , no collection of $k$ pairs made by the child contains the shoes from exactly $k$ of the adults is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"28"} +{"question":"In an isosceles trapezoid, the parallel bases have lengths $\\log 3$ and $\\log 192$ , and the altitude to these bases has length $\\log 16$ . The perimeter of the trapezoid can be written in the form $\\log 2^p 3^q$ , where $p$ and $q$ are positive integers. Find $p + q$ .","solution":"18"} +{"question":"Lines $l_1^{}$ and $l_2^{}$ both pass through the origin and make first-quadrant angles of $\\frac{\\pi}{70}$ and $\\frac{\\pi}{54}$ radians, respectively, with the positive x-axis. For any line $l^{}_{}$ , the transformation $R(l)^{}_{}$ produces another line as follows: $l^{}_{}$ is reflected in $l_1^{}$ , and the resulting line is reflected in $l_2^{}$ . Let $R^{(1)}(l)=R(l)^{}_{}$ and $R^{(n)}(l)^{}_{}=R\\left(R^{(n-1)}(l)\\right)$ . Given that $l^{}_{}$ is the line $y=\\frac{19}{92}x^{}_{}$ , find the smallest positive integer $m^{}_{}$ for which $R^{(m)}(l)=l^{}_{}$ .","solution":"945"} +{"question":"Find the number of permutations $x_1, x_2, x_3, x_4, x_5$ of numbers $1, 2, 3, 4, 5$ such that the sum of five products \\[x_1x_2x_3 + x_2x_3x_4 + x_3x_4x_5 + x_4x_5x_1 + x_5x_1x_2\\] is divisible by $3$ .","solution":"80"} +{"question":"Alfred and Bonnie play a game in which they take turns tossing a fair coin. The winner of a game is the first person to obtain a head. Alfred and Bonnie play this game several times with the stipulation that the loser of a game goes first in the next game. Suppose that Alfred goes first in the first game, and that the probability that he wins the sixth game is $m\/n\\,$ , where $m\\,$ and $n\\,$ are relatively prime positive integers. What are the last three digits of $m+n\\,$ ? ","solution":"93"} +{"question":"In convex hexagon $ABCDEF$ , all six sides are congruent, $\\angle A$ and $\\angle D$ are right angles, and $\\angle B, \\angle C, \\angle E,$ and $\\angle F$ are congruent. The area of the hexagonal region is $2116(\\sqrt{2}+1).$ Find $AB$ .","solution":"46"} +{"question":"Let $a, b, c,$ and $d$ be real numbers that satisfy the system of equations \\begin{align*} a + b &= -3, \\\\ ab + bc + ca &= -4, \\\\ abc + bcd + cda + dab &= 14, \\\\ abcd &= 30. \\end{align*} There exist relatively prime positive integers $m$ and $n$ such that \\[a^2 + b^2 + c^2 + d^2 = \\frac{m}{n}.\\] Find $m + n$ .","solution":"145"} +{"question":"A sphere is inscribed in the tetrahedron whose vertices are $A = (6,0,0), B = (0,4,0), C = (0,0,2),$ and $D = (0,0,0).$ The radius of the sphere is $m\/n,$ where $m$ and $n$ are relatively prime positive integers. Find $m + n.$","solution":"5"} +{"question":"Ms. Math's kindergarten class has $16$ registered students. The classroom has a very large number, $N$ , of play blocks which satisfies the conditions: (a) If $16$ , $15$ , or $14$ students are present in the class, then in each case all the blocks can be distributed in equal numbers to each student, and (b) There are three integers $0 < x < y < z < 14$ such that when $x$ , $y$ , or $z$ students are present and the blocks are distributed in equal numbers to each student, there are exactly three blocks left over. Find the sum of the distinct prime divisors of the least possible value of $N$ satisfying the above conditions.","solution":"148"} +{"question":"Nine tiles are numbered $1, 2, 3, \\cdots, 9,$ respectively. Each of three players randomly selects and keeps three of the tiles, and sums those three values. The probability that all three players obtain an odd sum is $m\/n,$ where $m$ and $n$ are relatively prime positive integers . Find $m+n.$","solution":"17"} +{"question":"Let $ABCD$ be an isosceles trapezoid with $\\overline{AD}||\\overline{BC}$ whose angle at the longer base $\\overline{AD}$ is $\\dfrac{\\pi}{3}$ . The diagonals have length $10\\sqrt {21}$ , and point $E$ is at distances $10\\sqrt {7}$ and $30\\sqrt {7}$ from vertices $A$ and $D$ , respectively. Let $F$ be the foot of the altitude from $C$ to $\\overline{AD}$ . The distance $EF$ can be expressed in the form $m\\sqrt {n}$ , where $m$ and $n$ are positive integers and $n$ is not divisible by the square of any prime. Find $m + n$ .","solution":"32"} +{"question":"An integer is called parity-monotonic if its decimal representation $a_{1}a_{2}a_{3}\\cdots a_{k}$ satisfies $a_{i}a_{i+1}$ if $a_{i}$ is even . How many four-digit parity-monotonic integers are there?","solution":"640"} +{"question":"A right prism with height $h$ has bases that are regular hexagons with sides of length $12$ . A vertex $A$ of the prism and its three adjacent vertices are the vertices of a triangular pyramid. The dihedral angle (the angle between the two planes) formed by the face of the pyramid that lies in a base of the prism and the face of the pyramid that does not contain $A$ measures $60^\\circ$ . Find $h^2$ .","solution":"108"} +{"question":"Consider sequences that consist entirely of $A$ 's and $B$ 's and that have the property that every run of consecutive $A$ 's has even length, and every run of consecutive $B$ 's has odd length. Examples of such sequences are $AA$ , $B$ , and $AABAA$ , while $BBAB$ is not such a sequence. How many such sequences have length 14?","solution":"172"} +{"question":"Let $v$ and $w$ be distinct, randomly chosen roots of the equation $z^{1997}-1=0$ . Let $m\/n$ be the probability that $\\sqrt{2+\\sqrt{3}}\\le |v+w|$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"582"} +{"question":"The sequence $(a_n)$ satisfies $a_0=0$ and $a_{n + 1} = \\frac{8}{5}a_n + \\frac{6}{5}\\sqrt{4^n - a_n^2}$ for $n \\geq 0$ . Find the greatest integer less than or equal to $a_{10}$ .","solution":"983"} +{"question":"Triangle $ABC$ lies in the Cartesian Plane and has an area of 70. The coordinates of $B$ and $C$ are $(12,19)$ and $(23,20),$ respectively, and the coordinates of $A$ are $(p,q).$ The line containing the median to side $BC$ has slope $-5.$ Find the largest possible value of $p+q.$","solution":"47"} +{"question":"Equilateral $\\triangle ABC$ is inscribed in a circle of radius 2. Extend $\\overline{AB}$ through $B$ to point $D$ so that $AD=13,$ and extend $\\overline{AC}$ through $C$ to point $E$ so that $AE = 11.$ Through $D,$ draw a line $l_1$ parallel to $\\overline{AE},$ and through $E,$ draw a line $l_2$ parallel to $\\overline{AD}.$ Let $F$ be the intersection of $l_1$ and $l_2.$ Let $G$ be the point on the circle that is collinear with $A$ and $F$ and distinct from $A.$ Given that the area of $\\triangle CBG$ can be expressed in the form $\\frac{p\\sqrt{q}}{r},$ where $p, q,$ and $r$ are positive integers, $p$ and $r$ are relatively prime, and $q$ is not divisible by the square of any prime, find $p+q+r.$","solution":"865"} +{"question":"Let $M_n$ be the $n \\times n$ matrix with entries as follows: for $1 \\le i \\le n$ , $m_{i,i} = 10$ ; for $1 \\le i \\le n - 1$ , $m_{i+1,i} = m_{i,i+1} = 3$ ; all other entries in $M_n$ are zero. Let $D_n$ be the determinant of matrix $M_n$ . Then $\\sum_{n=1}^{\\infty} \\frac{1}{8D_n+1}$ can be represented as $\\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p + q$ . Note: The determinant of the $1 \\times 1$ matrix $[a]$ is $a$ , and the determinant of the $2 \\times 2$ matrix $\\left[ {\\begin{array}{cc} a & b \\\\ c & d \\\\ \\end{array} } \\right] = ad - bc$ ; for $n \\ge 2$ , the determinant of an $n \\times n$ matrix with first row or first column $a_1$ $a_2$ $a_3$ $\\dots$ $a_n$ is equal to $a_1C_1 - a_2C_2 + a_3C_3 - \\dots + (-1)^{n+1}a_nC_n$ , where $C_i$ is the determinant of the $(n - 1) \\times (n - 1)$ matrix formed by eliminating the row and column containing $a_i$ .","solution":"73"} +{"question":"A set contains four numbers. The six pairwise sums of distinct elements of the set, in no particular order, are $189$ , $320$ , $287$ , $234$ , $x$ , and $y$ . Find the greatest possible value of $x+y$ .","solution":"791"} +{"question":"The polynomial $1-x+x^2-x^3+\\cdots+x^{16}-x^{17}$ may be written in the form $a_0+a_1y+a_2y^2+\\cdots +a_{16}y^{16}+a_{17}y^{17}$ , where $y=x+1$ and the $a_i$ 's are constants. Find the value of $a_2$ .","solution":"816"} +{"question":"Positive integers $a$ , $b$ , $c$ , and $d$ satisfy $a > b > c > d$ , $a + b + c + d = 2010$ , and $a^2 - b^2 + c^2 - d^2 = 2010$ . Find the number of possible values of $a$ .","solution":"501"} +{"question":"Let $x=\\frac{\\sum\\limits_{n=1}^{44} \\cos n^\\circ}{\\sum\\limits_{n=1}^{44} \\sin n^\\circ}$ . What is the greatest integer that does not exceed $100x$ ?","solution":"241"} +{"question":"It is given that $\\log_{6}a + \\log_{6}b + \\log_{6}c = 6$ , where $a$ , $b$ , and $c$ are positive integers that form an increasing geometric sequence and $b - a$ is the square of an integer. Find $a + b + c$ .","solution":"111"} +{"question":"A frog is placed at the origin on the number line , and moves according to the following rule: in a given move, the frog advances to either the closest point with a greater integer coordinate that is a multiple of $3$ , or to the closest point with a greater integer coordinate that is a multiple of $13$ . A move sequence is a sequence of coordinates which correspond to valid moves, beginning with $0$ , and ending with $39$ . For example, $0,\\ 3,\\ 6,\\ 13,\\ 15,\\ 26,\\ 39$ is a move sequence. How many move sequences are possible for the frog?","solution":"169"} +{"question":"The sequences of positive integers $1,a_2, a_3,...$ and $1,b_2, b_3,...$ are an increasing arithmetic sequence and an increasing geometric sequence, respectively. Let $c_n=a_n+b_n$ . There is an integer $k$ such that $c_{k-1}=100$ and $c_{k+1}=1000$ . Find $c_k$ .","solution":"262"} +{"question":"Let $A,B,C$ be angles of an acute triangle with \\begin{align*} \\cos^2 A + \\cos^2 B + 2 \\sin A \\sin B \\cos C &= \\frac{15}{8} \\text{ and} \\\\ \\cos^2 B + \\cos^2 C + 2 \\sin B \\sin C \\cos A &= \\frac{14}{9} \\end{align*} There are positive integers $p$ , $q$ , $r$ , and $s$ for which \\[\\cos^2 C + \\cos^2 A + 2 \\sin C \\sin A \\cos B = \\frac{p-q\\sqrt{r}}{s},\\] where $p+q$ and $s$ are relatively prime and $r$ is not divisible by the square of any prime. Find $p+q+r+s$ .","solution":"222"} +{"question":"A right circular cone has base radius $r$ and height $h$ . The cone lies on its side on a flat table. As the cone rolls on the surface of the table without slipping, the point where the cone's base meets the table traces a circular arc centered at the point where the vertex touches the table. The cone first returns to its original position on the table after making $17$ complete rotations. The value of $h\/r$ can be written in the form $m\\sqrt {n}$ , where $m$ and $n$ are positive integers and $n$ is not divisible by the square of any prime. Find $m + n$ .","solution":"14"} +{"question":"Beatrix is going to place six rooks on a $6 \\times 6$ chessboard where both the rows and columns are labeled $1$ to $6$ ; the rooks are placed so that no two rooks are in the same row or the same column. The value of a square is the sum of its row number and column number. The score of an arrangement of rooks is the least value of any occupied square. The average score over all valid configurations is $\\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"371"} +{"question":"What is the smallest positive integer with six positive odd integer divisors and twelve positive even integer divisors? ","solution":"180"} +{"question":"Let the set $S = \\{P_1, P_2, \\dots, P_{12}\\}$ consist of the twelve vertices of a regular $12$ -gon. A subset $Q$ of $S$ is called communal if there is a circle such that all points of $Q$ are inside the circle, and all points of $S$ not in $Q$ are outside of the circle. How many communal subsets are there? (Note that the empty set is a communal subset.)","solution":"134"} +{"question":"Find the least positive integer $n$ such that when $3^n$ is written in base $143$ , its two right-most digits in base $143$ are $01$ .","solution":"195"} +{"question":"For any finite set $S$ , let $|S|$ denote the number of elements in $S$ . Find the number of ordered pairs $(A,B)$ such that $A$ and $B$ are (not necessarily distinct) subsets of $\\{1,2,3,4,5\\}$ that satisfy \\[|A| \\cdot |B| = |A \\cap B| \\cdot |A \\cup B|\\]","solution":"454"} +{"question":"A hexagon that is inscribed in a circle has side lengths $22$ , $22$ , $20$ , $22$ , $22$ , and $20$ in that order. The radius of the circle can be written as $p+\\sqrt{q}$ , where $p$ and $q$ are positive integers. Find $p+q$ .","solution":"272"} +{"question":"Ten points in the plane are given, with no three collinear. Four distinct segments joining pairs of these points are chosen at random, all such segments being equally likely. The probability that some three of the segments form a triangle whose vertices are among the ten given points is $m\/n,$ where $m_{}$ and $n_{}$ are relatively prime positive integers. Find $m+n.$ ","solution":"489"} +{"question":"The rectangle $ABCD^{}_{}$ below has dimensions $AB^{}_{} = 12 \\sqrt{3}$ and $BC^{}_{} = 13 \\sqrt{3}$ . Diagonals $\\overline{AC}$ and $\\overline{BD}$ intersect at $P^{}_{}$ . If triangle $ABP^{}_{}$ is cut out and removed, edges $\\overline{AP}$ and $\\overline{BP}$ are joined, and the figure is then creased along segments $\\overline{CP}$ and $\\overline{DP}$ , we obtain a triangular pyramid, all four of whose faces are isosceles triangles. Find the volume of this pyramid. AIME 1990 Problem 14.png","solution":"594"} +{"question":"Let $p(x,y) = a_0 + a_1x + a_2y + a_3x^2 + a_4xy + a_5y^2 + a_6x^3 + a_7x^2y + a_8xy^2 + a_9y^3$ . Suppose that $p(0,0) = p(1,0) = p( - 1,0) = p(0,1) = p(0, - 1) = p(1,1) = p(1, - 1) = p(2,2) = 0$ . There is a point $\\left(\\frac {a}{c},\\frac {b}{c}\\right)$ for which $p\\left(\\frac {a}{c},\\frac {b}{c}\\right) = 0$ for all such polynomials, where $a$ , $b$ , and $c$ are positive integers, $a$ and $c$ are relatively prime, and $c > 1$ . Find $a + b + c$ .","solution":"40"} +{"question":"Given a circle of radius $\\sqrt{13}$ , let $A$ be a point at a distance $4 + \\sqrt{13}$ from the center $O$ of the circle. Let $B$ be the point on the circle nearest to point $A$ . A line passing through the point $A$ intersects the circle at points $K$ and $L$ . The maximum possible area for $\\triangle BKL$ can be written in the form $\\frac{a - b\\sqrt{c}}{d}$ , where $a$ , $b$ , $c$ , and $d$ are positive integers, $a$ and $d$ are relatively prime, and $c$ is not divisible by the square of any prime. Find $a+b+c+d$ .","solution":"146"} +{"question":"Square $S_{1}$ is $1\\times 1.$ For $i\\ge 1,$ the lengths of the sides of square $S_{i+1}$ are half the lengths of the sides of square $S_{i},$ two adjacent sides of square $S_{i}$ are perpendicular bisectors of two adjacent sides of square $S_{i+1},$ and the other two sides of square $S_{i+1},$ are the perpendicular bisectors of two adjacent sides of square $S_{i+2}.$ The total area enclosed by at least one of $S_{1}, S_{2}, S_{3}, S_{4}, S_{5}$ can be written in the form $m\/n,$ where $m$ and $n$ are relatively prime positive integers. Find $m-n.$ AIME 1995 Problem 1.png","solution":"255"} +{"question":"Two spheres with radii $36$ and one sphere with radius $13$ are each externally tangent to the other two spheres and to two different planes $\\mathcal{P}$ and $\\mathcal{Q}$ . The intersection of planes $\\mathcal{P}$ and $\\mathcal{Q}$ is the line $\\ell$ . The distance from line $\\ell$ to the point where the sphere with radius $13$ is tangent to plane $\\mathcal{P}$ is $\\tfrac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"335"} +{"question":"Let $x,$ $y,$ and $z$ be positive real numbers that satisfy \\[2\\log_{x}(2y) = 2\\log_{2x}(4z) = \\log_{2x^4}(8yz) \\ne 0.\\] The value of $xy^5z$ can be expressed in the form $\\frac{1}{2^{p\/q}},$ where $p$ and $q$ are relatively prime positive integers. Find $p+q.$","solution":"49"} +{"question":"Rectangle $ABCD_{}^{}$ has sides $\\overline {AB}$ of length 4 and $\\overline {CB}$ of length 3. Divide $\\overline {AB}$ into 168 congruent segments with points $A_{}^{}=P_0, P_1, \\ldots, P_{168}=B$ , and divide $\\overline {CB}$ into 168 congruent segments with points $C_{}^{}=Q_0, Q_1, \\ldots, Q_{168}=B$ . For $1_{}^{} \\le k \\le 167$ , draw the segments $\\overline {P_kQ_k}$ . Repeat this construction on the sides $\\overline {AD}$ and $\\overline {CD}$ , and then draw the diagonal $\\overline {AC}$ . Find the sum of the lengths of the 335 parallel segments drawn.","solution":"840"} +{"question":"Two different points, $C$ and $D$ , lie on the same side of line $AB$ so that $\\triangle ABC$ and $\\triangle BAD$ are congruent with $AB=9,BC=AD=10$ , and $CA=DB=17$ . The intersection of these two triangular regions has area $\\tfrac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"59"} +{"question":"A bug starts at a vertex of an equilateral triangle. On each move, it randomly selects one of the two vertices where it is not currently located, and crawls along a side of the triangle to that vertex. Given that the probability that the bug moves to its starting vertex on its tenth move is $m\/n,$ where $m$ and $n$ are relatively prime positive integers, find $m + n.$ ","solution":"683"} +{"question":"A triangular array of numbers has a first row consisting of the odd integers $1,3,5,\\ldots,99$ in increasing order. Each row below the first has one fewer entry than the row above it, and the bottom row has a single entry. Each entry in any row after the top row equals the sum of the two entries diagonally above it in the row immediately above it. How many entries in the array are multiples of $67$ ?","solution":"17"} +{"question":"A container in the shape of a right circular cone is 12 inches tall and its base has a 5-inch radius. The liquid that is sealed inside is 9 inches deep when the cone is held with its point down and its base horizontal. When the liquid is held with its point up and its base horizontal, the height of the liquid is $m - n\\sqrt [3]{p},$ where $m,$ $n,$ and $p$ are positive integers and $p$ is not divisible by the cube of any prime number. Find $m + n + p$ .","solution":"52"} +{"question":"Find the sum of all positive integers $n$ for which $n^2-19n+99$ is a perfect square.","solution":"38"} +{"question":"A sequence of integers $a_1, a_2, a_3, \\ldots$ is chosen so that $a_n = a_{n - 1} - a_{n - 2}$ for each $n \\ge 3$ . What is the sum of the first $2001$ terms of this sequence if the sum of the first $1492$ terms is $1985$ , and the sum of the first $1985$ terms is $1492$ ?","solution":"986"} +{"question":"The nine horizontal and nine vertical lines on an $8\\times8$ checkerboard form $r$ rectangles, of which $s$ are squares. The number $s\/r$ can be written in the form $m\/n,$ where $m$ and $n$ are relatively prime positive integers. Find $m + n.$","solution":"125"} +{"question":"In $\\triangle RED$ , $\\measuredangle DRE=75^{\\circ}$ and $\\measuredangle RED=45^{\\circ}$ . $RD=1$ . Let $M$ be the midpoint of segment $\\overline{RD}$ . Point $C$ lies on side $\\overline{ED}$ such that $\\overline{RC}\\perp\\overline{EM}$ . Extend segment $\\overline{DE}$ through $E$ to point $A$ such that $CA=AR$ . Then $AE=\\frac{a-\\sqrt{b}}{c}$ , where $a$ and $c$ are relatively prime positive integers, and $b$ is a positive integer. Find $a+b+c$ .","solution":"56"} +{"question":"Let $S$ be the set of positive integer divisors of $20^9.$ Three numbers are chosen independently and at random with replacement from the set $S$ and labeled $a_1,a_2,$ and $a_3$ in the order they are chosen. The probability that both $a_1$ divides $a_2$ and $a_2$ divides $a_3$ is $\\tfrac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m.$","solution":"77"} +{"question":"Find the value of $10\\cot(\\cot^{-1}3+\\cot^{-1}7+\\cot^{-1}13+\\cot^{-1}21).$","solution":"15"} +{"question":"Let $\\overline{AB}$ be a chord of a circle $\\omega$ , and let $P$ be a point on the chord $\\overline{AB}$ . Circle $\\omega_1$ passes through $A$ and $P$ and is internally tangent to $\\omega$ . Circle $\\omega_2$ passes through $B$ and $P$ and is internally tangent to $\\omega$ . Circles $\\omega_1$ and $\\omega_2$ intersect at points $P$ and $Q$ . Line $PQ$ intersects $\\omega$ at $X$ and $Y$ . Assume that $AP=5$ , $PB=3$ , $XY=11$ , and $PQ^2 = \\tfrac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"65"} +{"question":"In convex quadrilateral $ABCD, \\angle A \\cong \\angle C, AB = CD = 180,$ and $AD \\neq BC.$ The perimeter of $ABCD$ is 640. Find $\\lfloor 1000 \\cos A \\rfloor.$ (The notation $\\lfloor x \\rfloor$ means the greatest integer that is less than or equal to $x.$ )","solution":"777"} +{"question":"Given a real number $x,$ let $\\lfloor x \\rfloor$ denote the greatest integer less than or equal to $x.$ For a certain integer $k,$ there are exactly $70$ positive integers $n_{1}, n_{2}, \\ldots, n_{70}$ such that $k=\\lfloor\\sqrt[3]{n_{1}}\\rfloor = \\lfloor\\sqrt[3]{n_{2}}\\rfloor = \\cdots = \\lfloor\\sqrt[3]{n_{70}}\\rfloor$ and $k$ divides $n_{i}$ for all $i$ such that $1 \\leq i \\leq 70.$ Find the maximum value of $\\frac{n_{i}}{k}$ for $1\\leq i \\leq 70.$","solution":"553"} +{"question":"A tennis player computes her win ratio by dividing the number of matches she has won by the total number of matches she has played. At the start of a weekend, her win ratio is exactly $0.500$ . During the weekend, she plays four matches, winning three and losing one. At the end of the weekend, her win ratio is greater than $.503$ . What's the largest number of matches she could've won before the weekend began?","solution":"164"} +{"question":"Faces $ABC^{}_{}$ and $BCD^{}_{}$ of tetrahedron $ABCD^{}_{}$ meet at an angle of $30^\\circ$ . The area of face $ABC^{}_{}$ is $120^{}_{}$ , the area of face $BCD^{}_{}$ is $80^{}_{}$ , and $BC=10^{}_{}$ . Find the volume of the tetrahedron.","solution":"320"} +{"question":"Suppose $x$ is in the interval $[0,\\pi\/2]$ and $\\log_{24 \\sin x} (24 \\cos x) = \\frac{3}{2}$ . Find $24 \\cot^2 x$ .","solution":"192"} +{"question":"A point whose coordinates are both integers is called a lattice point. How many lattice points lie on the hyperbola $x^2 - y^2 = 2000^2$ ?","solution":"98"} +{"question":"The product $N$ of three positive integers is 6 times their sum, and one of the integers is the sum of the other two. Find the sum of all possible values of $N$ .","solution":"336"} +{"question":"Two congruent right circular cones each with base radius $3$ and height $8$ have axes of symmetry that intersect at right angles at a point in the interior of the cones a distance $3$ from the base of each cone. A sphere with radius $r$ lies within both cones. The maximum possible value of $r^2$ is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"298"} +{"question":"Define an ordered quadruple of integers $(a, b, c, d)$ as interesting if $1 \\le ab+c$ . How many interesting ordered quadruples are there?","solution":"80"} +{"question":"The system of equations \\begin{eqnarray*}\\log_{10}(2000xy) - (\\log_{10}x)(\\log_{10}y) & = & 4 \\\\ \\log_{10}(2yz) - (\\log_{10}y)(\\log_{10}z) & = & 1 \\\\ \\log_{10}(zx) - (\\log_{10}z)(\\log_{10}x) & = & 0 \\\\ \\end{eqnarray*} has two solutions $(x_{1},y_{1},z_{1})$ and $(x_{2},y_{2},z_{2})$ . Find $y_{1} + y_{2}$ .","solution":"25"} +{"question":"Let $\\mathcal{T}$ be the set of ordered triples $(x,y,z)$ of nonnegative real numbers that lie in the plane $x+y+z=1.$ Let us say that $(x,y,z)$ supports $(a,b,c)$ when exactly two of the following are true: $x\\ge a, y\\ge b, z\\ge c.$ Let $\\mathcal{S}$ consist of those triples in $\\mathcal{T}$ that support $\\left(\\frac 12,\\frac 13,\\frac 16\\right).$ The area of $\\mathcal{S}$ divided by the area of $\\mathcal{T}$ is $m\/n,$ where $m_{}$ and $n_{}$ are relatively prime positive integers, find $m+n.$","solution":"25"} +{"question":"Let $S$ be the sum of all numbers of the form $\\frac{a}{b}$ , where $a$ and $b$ are relatively prime positive divisors of $1000.$ What is the greatest integer that does not exceed $\\frac{S}{10}$ ?","solution":"248"} +{"question":"In triangle $ABC$ , $AB=20$ and $AC=11$ . The angle bisector of angle $A$ intersects $BC$ at point $D$ , and point $M$ is the midpoint of $AD$ . Let $P$ be the point of intersection of $AC$ and the line $BM$ . The ratio of $CP$ to $PA$ can be expressed in the form $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"51"} +{"question":"Let $a$ and $b$ be positive real numbers with $a \\ge b$ . Let $\\rho$ be the maximum possible value of $\\dfrac{a}{b}$ for which the system of equations \\[a^2 + y^2 = b^2 + x^2 = (a-x)^2 + (b-y)^2\\] has a solution $(x,y)$ satisfying $0 \\le x < a$ and $0 \\le y < b$ . Then $\\rho^2$ can be expressed as a fraction $\\dfrac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"7"} +{"question":"An integer between $1000$ and $9999,$ inclusive, is called balanced if the sum of its two leftmost digits equals the sum of its two rightmost digits. How many balanced integers are there?","solution":"615"} +{"question":"Each unit square of a 3-by-3 unit-square grid is to be colored either blue or red. For each square, either color is equally likely to be used. The probability of obtaining a grid that does not have a 2-by-2 red square is $\\frac {m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"929"} +{"question":"A function $f$ is defined for all real numbers and satisfies $f(2+x)=f(2-x)$ and $f(7+x)=f(7-x)$ for all $x$ . If $x=0$ is a root for $f(x)=0$ , what is the least number of roots $f(x)=0$ must have in the interval $-1000\\leq x \\leq 1000$ ?","solution":"401"} +{"question":"A plane contains $40$ lines, no $2$ of which are parallel. Suppose that there are $3$ points where exactly $3$ lines intersect, $4$ points where exactly $4$ lines intersect, $5$ points where exactly $5$ lines intersect, $6$ points where exactly $6$ lines intersect, and no points where more than $6$ lines intersect. Find the number of points where exactly $2$ lines intersect.","solution":"607"} +{"question":"Complex numbers $a,$ $b,$ and $c$ are zeros of a polynomial $P(z) = z^3 + qz + r,$ and $|a|^2 + |b|^2 + |c|^2 = 250.$ The points corresponding to $a,$ $b,$ and $c$ in the complex plane are the vertices of a right triangle with hypotenuse $h.$ Find $h^2.$","solution":"375"} +{"question":"Let $ABC$ be an equilateral triangle, and let $D$ and $F$ be points on sides $BC$ and $AB$ , respectively, with $FA = 5$ and $CD = 2$ . Point $E$ lies on side $CA$ such that angle $DEF = 60^{\\circ}$ . The area of triangle $DEF$ is $14\\sqrt{3}$ . The two possible values of the length of side $AB$ are $p \\pm q \\sqrt{r}$ , where $p$ and $q$ are rational, and $r$ is an integer not divisible by the square of a prime. Find $r$ .","solution":"989"} +{"question":"Suppose that $x$ , $y$ , and $z$ are complex numbers such that $xy = -80 - 320i$ , $yz = 60$ , and $zx = -96 + 24i$ , where $i$ $=$ $\\sqrt{-1}$ . Then there are real numbers $a$ and $b$ such that $x + y + z = a + bi$ . Find $a^2 + b^2$ .","solution":"74"} +{"question":"Real numbers $r$ and $s$ are roots of $p(x)=x^3+ax+b$ , and $r+4$ and $s-3$ are roots of $q(x)=x^3+ax+b+240$ . Find the sum of all possible values of $|b|$ .","solution":"420"} +{"question":"Find the sum of all positive integers $n$ such that $\\sqrt{n^2+85n+2017}$ is an integer.","solution":"195"} +{"question":"Each of the 2001 students at a high school studies either Spanish or French, and some study both. The number who study Spanish is between 80 percent and 85 percent of the school population, and the number who study French is between 30 percent and 40 percent. Let $m$ be the smallest number of students who could study both languages, and let $M$ be the largest number of students who could study both languages. Find $M-m$ .","solution":"298"} +{"question":"Eight spheres of radius 100 are placed on a flat surface so that each sphere is tangent to two others and their centers are the vertices of a regular octagon . A ninth sphere is placed on the flat surface so that it is tangent to each of the other eight spheres. The radius of this last sphere is $a +b\\sqrt {c},$ where $a, b,$ and $c$ are positive integers , and $c$ is not divisible by the square of any prime . Find $a + b + c$ .","solution":"152"} +{"question":"The sum of the areas of all triangles whose vertices are also vertices of a 1 by 1 by 1 cube is $m + \\sqrt{n} + \\sqrt{p},$ where $m, n,$ and $p$ are integers. Find $m + n + p.$","solution":"348"} +{"question":"Let $S^{}_{}$ be a subset of $\\{1,2,3^{}_{},\\ldots,1989\\}$ such that no two members of $S^{}_{}$ differ by $4^{}_{}$ or $7^{}_{}$ . What is the largest number of elements $S^{}_{}$ can have?","solution":"905"} +{"question":"For any positive integer $k$ , let $f_1(k)$ denote the square of the sum of the digits of $k$ . For $n \\ge 2$ , let $f_n(k) = f_1(f_{n - 1}(k))$ . Find $f_{1988}(11)$ .","solution":"169"} +{"question":"Let $A$ and $B$ be the endpoints of a semicircular arc of radius $2$ . The arc is divided into seven congruent arcs by six equally spaced points $C_1,C_2,\\dots,C_6$ . All chords of the form $\\overline{AC_i}$ or $\\overline{BC_i}$ are drawn. Let $n$ be the product of the lengths of these twelve chords. Find the remainder when $n$ is divided by $1000$ .","solution":"672"} +{"question":"Find $(\\log_2 x)^2$ if $\\log_2 (\\log_8 x) = \\log_8 (\\log_2 x)$ .","solution":"27"} +{"question":"How many positive integer divisors of $2004^{2004}$ are divisible by exactly 2004 positive integers?","solution":"54"} +{"question":"Find the number of ordered pairs of integers $(a,b)$ such that the sequence \\[3,4,5,a,b,30,40,50\\] is strictly increasing and no set of four (not necessarily consecutive) terms forms an arithmetic progression.","solution":"228"} +{"question":"In a new school, $40$ percent of the students are freshmen, $30$ percent are sophomores, $20$ percent are juniors, and $10$ percent are seniors. All freshmen are required to take Latin, and $80$ percent of sophomores, $50$ percent of the juniors, and $20$ percent of the seniors elect to take Latin. The probability that a randomly chosen Latin student is a sophomore is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"25"} +{"question":"Three of the edges of a cube are $\\overline{AB}, \\overline{BC},$ and $\\overline{CD},$ and $\\overline{AD}$ is an interior diagonal . Points $P, Q,$ and $R$ are on $\\overline{AB}, \\overline{BC},$ and $\\overline{CD},$ respectively, so that $AP = 5, PB = 15, BQ = 15,$ and $CR = 10.$ What is the area of the polygon that is the intersection of plane $PQR$ and the cube?","solution":"525"} +{"question":"For each positive integer $p$ , let $b(p)$ denote the unique positive integer $k$ such that $|k-\\sqrt{p}| < \\frac{1}{2}$ . For example, $b(6) = 2$ and $b(23) = 5$ . If $S = \\sum_{p=1}^{2007} b(p),$ find the remainder when $S$ is divided by 1000.","solution":"955"} +{"question":"In an increasing sequence of four positive integers, the first three terms form an arithmetic progression, the last three terms form a geometric progression, and the first and fourth terms differ by $30.$ Find the sum of the four terms.","solution":"129"} +{"question":"Let $z_1,z_2,z_3,\\dots,z_{12}$ be the 12 zeroes of the polynomial $z^{12}-2^{36}$ . For each $j$ , let $w_j$ be one of $z_j$ or $i z_j$ . Then the maximum possible value of the real part of $\\sum_{j=1}^{12} w_j$ can be written as $m+\\sqrt{n}$ where $m$ and $n$ are positive integers. Find $m+n$ .","solution":"784"} +{"question":"For $-1 2$ define $a_{n}$ recursively to be the remainder when $4(a_{n-1} + a_{n-2} + a_{n-3})$ is divided by $11$ . Find $a_{2018} \\cdot a_{2020} \\cdot a_{2022}$ .","solution":"112"} +{"question":"A circle circumscribes an isosceles triangle whose two congruent angles have degree measure $x$ . Two points are chosen independently and uniformly at random on the circle, and a chord is drawn between them. The probability that the chord intersects the triangle is $\\frac{14}{25}$ . Find the difference between the largest and smallest possible values of $x$ .","solution":"48"} +{"question":"A mail carrier delivers mail to the nineteen houses on the east side of Elm Street. The carrier notices that no two adjacent houses ever get mail on the same day, but that there are never more than two houses in a row that get no mail on the same day. How many different patterns of mail delivery are possible? ","solution":"351"} +{"question":"There is a complex number $z$ with imaginary part $164$ and a positive integer $n$ such that \\[\\frac {z}{z + n} = 4i.\\] Find $n$ .","solution":"697"} +{"question":"An ordered pair $(m,n)$ of non-negative integers is called \"simple\" if the addition $m+n$ in base $10$ requires no carrying. Find the number of simple ordered pairs of non-negative integers that sum to $1492$ .","solution":"300"} +{"question":"Squares $S_1$ and $S_2$ are inscribed in right triangle $ABC$ , as shown in the figures below. Find $AC + CB$ if area $(S_1) = 441$ and area $(S_2) = 440$ . AIME 1987 Problem 15.png","solution":"462"} +{"question":"A solitaire game is played as follows. Six distinct pairs of matched tiles are placed in a bag. The player randomly draws tiles one at a time from the bag and retains them, except that matching tiles are put aside as soon as they appear in the player's hand. The game ends if the player ever holds three tiles, no two of which match; otherwise the drawing continues until the bag is empty. The probability that the bag will be emptied is $p\/q,\\,$ where $p\\,$ and $q\\,$ are relatively prime positive integers. Find $p+q.\\,$ ","solution":"394"} +{"question":"A frog begins at $P_0 = (0,0)$ and makes a sequence of jumps according to the following rule: from $P_n = (x_n, y_n),$ the frog jumps to $P_{n+1},$ which may be any of the points $(x_n + 7, y_n + 2),$ $(x_n + 2, y_n + 7),$ $(x_n - 5, y_n - 10),$ or $(x_n - 10, y_n - 5).$ There are $M$ points $(x, y)$ with $|x| + |y| \\le 100$ that can be reached by a sequence of such jumps. Find the remainder when $M$ is divided by $1000.$","solution":"373"} +{"question":"Let $m$ be the largest real solution to the equation \\[\\dfrac{3}{x-3} + \\dfrac{5}{x-5} + \\dfrac{17}{x-17} + \\dfrac{19}{x-19} = x^2 - 11x - 4\\] There are positive integers $a, b,$ and $c$ such that $m = a + \\sqrt{b + \\sqrt{c}}$ . Find $a+b+c$ .","solution":"263"} +{"question":"The increasing sequence $2,3,5,6,7,10,11,\\ldots$ consists of all positive integers that are neither the square nor the cube of a positive integer. Find the 500th term of this sequence.","solution":"528"} +{"question":"Circles $\\mathcal{P}$ and $\\mathcal{Q}$ have radii $1$ and $4$ , respectively, and are externally tangent at point $A$ . Point $B$ is on $\\mathcal{P}$ and point $C$ is on $\\mathcal{Q}$ such that $BC$ is a common external tangent of the two circles. A line $\\ell$ through $A$ intersects $\\mathcal{P}$ again at $D$ and intersects $\\mathcal{Q}$ again at $E$ . Points $B$ and $C$ lie on the same side of $\\ell$ , and the areas of $\\triangle DBA$ and $\\triangle ACE$ are equal. This common area is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ . [asy] import cse5; pathpen=black; pointpen=black; size(6cm); pair E = IP(L((-.2476,1.9689),(0.8,1.6),-3,5.5),CR((4,4),4)), D = (-.2476,1.9689); filldraw(D--(0.8,1.6)--(0,0)--cycle,gray(0.7)); filldraw(E--(0.8,1.6)--(4,0)--cycle,gray(0.7)); D(CR((0,1),1)); D(CR((4,4),4,150,390)); D(L(MP(\"D\",D(D),N),MP(\"A\",D((0.8,1.6)),NE),1,5.5)); D((-1.2,0)--MP(\"B\",D((0,0)),S)--MP(\"C\",D((4,0)),S)--(8,0)); D(MP(\"E\",E,N)); [\/asy]","solution":"129"} +{"question":"When a right triangle is rotated about one leg, the volume of the cone produced is $800\\pi \\;\\textrm{cm}^3$ . When the triangle is rotated about the other leg, the volume of the cone produced is $1920\\pi \\;\\textrm{cm}^3$ . What is the length (in cm) of the hypotenuse of the triangle?","solution":"26"} +{"question":"Circles $\\mathcal{C}_{1}$ and $\\mathcal{C}_{2}$ intersect at two points, one of which is $(9,6)$ , and the product of the radii is $68$ . The x-axis and the line $y = mx$ , where $m > 0$ , are tangent to both circles. It is given that $m$ can be written in the form $a\\sqrt {b}\/c$ , where $a$ , $b$ , and $c$ are positive integers, $b$ is not divisible by the square of any prime, and $a$ and $c$ are relatively prime. Find $a + b + c$ .","solution":"282"} +{"question":"The vertices of $\\triangle ABC$ are $A = (0,0)\\,$ , $B = (0,420)\\,$ , and $C = (560,0)\\,$ . The six faces of a die are labeled with two $A\\,$ 's, two $B\\,$ 's, and two $C\\,$ 's. Point $P_1 = (k,m)\\,$ is chosen in the interior of $\\triangle ABC$ , and points $P_2\\,$ , $P_3\\,$ , $P_4, \\dots$ are generated by rolling the die repeatedly and applying the rule: If the die shows label $L\\,$ , where $L \\in \\{A, B, C\\}$ , and $P_n\\,$ is the most recently obtained point, then $P_{n + 1}^{}$ is the midpoint of $\\overline{P_n L}$ . Given that $P_7 = (14,92)\\,$ , what is $k + m\\,$ ?","solution":"344"} +{"question":"A sequence of numbers $x_{1},x_{2},x_{3},\\ldots,x_{100}$ has the property that, for every integer $k$ between $1$ and $100,$ inclusive, the number $x_{k}$ is $k$ less than the sum of the other $99$ numbers. Given that $x_{50} = \\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers, find $m + n$ .","solution":"173"} +{"question":"For each positive integer $n$ let $a_n$ be the least positive integer multiple of $23$ such that $a_n \\equiv 1 \\pmod{2^n}.$ Find the number of positive integers $n$ less than or equal to $1000$ that satisfy $a_n = a_{n+1}.$","solution":"363"} +{"question":"Maya lists all the positive divisors of $2010^2$ . She then randomly selects two distinct divisors from this list. Let $p$ be the probability that exactly one of the selected divisors is a perfect square. The probability $p$ can be expressed in the form $\\frac {m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"107"} +{"question":"A block of cheese in the shape of a rectangular solid measures $10$ cm by $13$ cm by $14$ cm. Ten slices are cut from the cheese. Each slice has a width of $1$ cm and is cut parallel to one face of the cheese. The individual slices are not necessarily parallel to each other. What is the maximum possible volume in cubic cm of the remaining block of cheese after ten slices have been cut off?","solution":"729"} +{"question":"Two unit squares are selected at random without replacement from an $n \\times n$ grid of unit squares. Find the least positive integer $n$ such that the probability that the two selected unit squares are horizontally or vertically adjacent is less than $\\frac{1}{2015}$ .","solution":"90"} +{"question":"A pyramid has a triangular base with side lengths $20$ , $20$ , and $24$ . The three edges of the pyramid from the three corners of the base to the fourth vertex of the pyramid all have length $25$ . The volume of the pyramid is $m\\sqrt{n}$ , where $m$ and $n$ are positive integers, and $n$ is not divisible by the square of any prime. Find $m+n$ .","solution":"803"} +{"question":"Let $C$ be the coefficient of $x^2$ in the expansion of the product $(1 - x)(1 + 2x)(1 - 3x)\\cdots(1 + 14x)(1 - 15x).$ Find $|C|.$","solution":"588"} +{"question":"Zou and Chou are practicing their $100$ -meter sprints by running $6$ races against each other. Zou wins the first race, and after that, the probability that one of them wins a race is $\\frac23$ if they won the previous race but only $\\frac13$ if they lost the previous race. The probability that Zou will win exactly $5$ of the $6$ races is $\\frac mn$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"97"} +{"question":"Triangle $ABC$ has $AB=21$ , $AC=22$ and $BC=20$ . Points $D$ and $E$ are located on $\\overline{AB}$ and $\\overline{AC}$ , respectively, such that $\\overline{DE}$ is parallel to $\\overline{BC}$ and contains the center of the inscribed circle of triangle $ABC$ . Then $DE=\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"923"} +{"question":"A fair die is rolled four times. The probability that each of the final three rolls is at least as large as the roll preceding it may be expressed in the form $m\/n$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ . ","solution":"79"} +{"question":"Each of two boxes contains both black and white marbles, and the total number of marbles in the two boxes is $25.$ One marble is taken out of each box randomly. The probability that both marbles are black is $\\frac{27}{50},$ and the probability that both marbles are white is $\\frac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. What is $m + n$ ?","solution":"26"} +{"question":"Let $N$ be the number of complex numbers $z$ with the properties that $|z|=1$ and $z^{6!}-z^{5!}$ is a real number. Find the remainder when $N$ is divided by $1000$ .","solution":"440"} +{"question":"A triangle has vertices $P_{}^{}=(-8,5)$ , $Q_{}^{}=(-15,-19)$ , and $R_{}^{}=(1,-7)$ . The equation of the bisector of $\\angle P$ can be written in the form $ax+2y+c=0_{}^{}$ . Find $a+c_{}^{}$ .","solution":"89"} +{"question":"In $\\triangle{ABC}$ with $AB = 12$ , $BC = 13$ , and $AC = 15$ , let $M$ be a point on $\\overline{AC}$ such that the incircles of $\\triangle{ABM}$ and $\\triangle{BCM}$ have equal radii. Then $\\frac{AM}{CM} = \\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p + q$ .","solution":"45"} +{"question":"Let $S_i$ be the set of all integers $n$ such that $100i\\leq n < 100(i + 1)$ . For example, $S_4$ is the set ${400,401,402,\\ldots,499}$ . How many of the sets $S_0, S_1, S_2, \\ldots, S_{999}$ do not contain a perfect square?","solution":"708"} +{"question":"Find the three-digit positive integer $\\underline{a}\\,\\underline{b}\\,\\underline{c}$ whose representation in base nine is $\\underline{b}\\,\\underline{c}\\,\\underline{a}_{\\,\\text{nine}},$ where $a,$ $b,$ and $c$ are (not necessarily distinct) digits. ","solution":"227"} +{"question":"An $a \\times b \\times c$ rectangular box is built from $a \\cdot b \\cdot c$ unit cubes. Each unit cube is colored red, green, or yellow. Each of the $a$ layers of size $1 \\times b \\times c$ parallel to the $(b \\times c)$ faces of the box contains exactly $9$ red cubes, exactly $12$ green cubes, and some yellow cubes. Each of the $b$ layers of size $a \\times 1 \\times c$ parallel to the $(a \\times c)$ faces of the box contains exactly $20$ green cubes, exactly $25$ yellow cubes, and some red cubes. Find the smallest possible volume of the box.","solution":"180"} +{"question":"In trapezoid $ABCD$ with $\\overline{BC}\\parallel\\overline{AD}$ , let $BC = 1000$ and $AD = 2008$ . Let $\\angle A = 37^\\circ$ , $\\angle D = 53^\\circ$ , and $M$ and $N$ be the midpoints of $\\overline{BC}$ and $\\overline{AD}$ , respectively. Find the length $MN$ .","solution":"504"} +{"question":"Call a three-term strictly increasing arithmetic sequence of integers special if the sum of the squares of the three terms equals the product of the middle term and the square of the common difference. Find the sum of the third terms of all special sequences. ","solution":"31"} +{"question":"Let $r$ , $s$ , and $t$ be the three roots of the equation \\[8x^3 + 1001x + 2008 = 0.\\] Find $(r + s)^3 + (s + t)^3 + (t + r)^3$ .","solution":"753"} +{"question":"The real root of the equation $8x^3-3x^2-3x-1=0$ can be written in the form $\\frac{\\sqrt[3]{a}+\\sqrt[3]{b}+1}{c}$ , where $a$ , $b$ , and $c$ are positive integers. Find $a+b+c$ .","solution":"98"} +{"question":"Find the sum of all positive two-digit integers that are divisible by each of their digits. ","solution":"630"} +{"question":"For positive integers $n$ and $k$ , let $f(n, k)$ be the remainder when $n$ is divided by $k$ , and for $n > 1$ let $F(n) = \\max_{\\substack{1\\le k\\le \\frac{n}{2}}} f(n, k)$ . Find the remainder when $\\sum\\limits_{n=20}^{100} F(n)$ is divided by $1000$ .","solution":"512"} +{"question":"For a positive integer $p$ , define the positive integer $n$ to be $p$ -safe if $n$ differs in absolute value by more than $2$ from all multiples of $p$ . For example, the set of $10$ -safe numbers is $\\{ 3, 4, 5, 6, 7, 13, 14, 15, 16, 17, 23, \\ldots\\}$ . Find the number of positive integers less than or equal to $10,000$ which are simultaneously $7$ -safe, $11$ -safe, and $13$ -safe.","solution":"958"} +{"question":"Consider the L-shaped region formed by three unit squares joined at their sides, as shown below. Two points $A$ and $B$ are chosen independently and uniformly at random from inside the region. The probability that the midpoint of $\\overline{AB}$ also lies inside this L-shaped region can be expressed as $\\frac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$ [asy] unitsize(2cm); draw((0,0)--(2,0)--(2,1)--(1,1)--(1,2)--(0,2)--cycle); draw((0,1)--(1,1)--(1,0),dashed); [\/asy]","solution":"35"} +{"question":"Of the students attending a school party, $60\\%$ of the students are girls, and $40\\%$ of the students like to dance. After these students are joined by $20$ more boy students, all of whom like to dance, the party is now $58\\%$ girls. How many students now at the party like to dance?","solution":"252"} +{"question":"The points $A$ , $B$ and $C$ lie on the surface of a sphere with center $O$ and radius $20$ . It is given that $AB=13$ , $BC=14$ , $CA=15$ , and that the distance from $O$ to triangle $ABC$ is $\\frac{m\\sqrt{n}}k$ , where $m$ , $n$ , and $k$ are positive integers, $m$ and $k$ are relatively prime, and $n$ is not divisible by the square of any prime. Find $m+n+k$ .","solution":"118"} +{"question":"Find the sum of the values of $x$ such that $\\cos^3 3x+ \\cos^3 5x = 8 \\cos^3 4x \\cos^3 x,$ where $x$ is measured in degrees and $100< x< 200.$","solution":"906"} +{"question":"In triangle $ABC$ , $AB=\\sqrt{30}$ , $AC=\\sqrt{6}$ , and $BC=\\sqrt{15}$ . There is a point $D$ for which $\\overline{AD}$ bisects $\\overline{BC}$ , and $\\angle ADB$ is a right angle. The ratio \\[\\dfrac{\\text{Area}(\\triangle ADB)}{\\text{Area}(\\triangle ABC)}\\] can be written in the form $\\dfrac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"65"} +{"question":"In equilateral $\\triangle ABC$ let points $D$ and $E$ trisect $\\overline{BC}$ . Then $\\sin(\\angle DAE)$ can be expressed in the form $\\frac{a\\sqrt{b}}{c}$ , where $a$ and $c$ are relatively prime positive integers, and $b$ is an integer that is not divisible by the square of any prime. Find $a+b+c$ . ","solution":"20"} +{"question":"For certain pairs $(m,n)$ of positive integers with $m\\geq n$ there are exactly $50$ distinct positive integers $k$ such that $|\\log m - \\log k| < \\log n$ . Find the sum of all possible values of the product $m \\cdot n$ .","solution":"125"} +{"question":"What is the largest even integer that cannot be written as the sum of two odd composite numbers? ","solution":"38"} +{"question":"Equilateral triangle $ABC$ has side length $840$ . Point $D$ lies on the same side of line $BC$ as $A$ such that $\\overline{BD} \\perp \\overline{BC}$ . The line $\\ell$ through $D$ parallel to line $BC$ intersects sides $\\overline{AB}$ and $\\overline{AC}$ at points $E$ and $F$ , respectively. Point $G$ lies on $\\ell$ such that $F$ is between $E$ and $G$ , $\\triangle AFG$ is isosceles, and the ratio of the area of $\\triangle AFG$ to the area of $\\triangle BED$ is $8:9$ . Find $AF$ . [asy] pair A,B,C,D,E,F,G; B=origin; A=5*dir(60); C=(5,0); E=0.6*A+0.4*B; F=0.6*A+0.4*C; G=rotate(240,F)*A; D=extension(E,F,B,dir(90)); draw(D--G--A,grey); draw(B--0.5*A+rotate(60,B)*A*0.5,grey); draw(A--B--C--cycle,linewidth(1.5)); dot(A^^B^^C^^D^^E^^F^^G); label(\"$A$\",A,dir(90)); label(\"$B$\",B,dir(225)); label(\"$C$\",C,dir(-45)); label(\"$D$\",D,dir(180)); label(\"$E$\",E,dir(-45)); label(\"$F$\",F,dir(225)); label(\"$G$\",G,dir(0)); label(\"$\\ell$\",midpoint(E--F),dir(90)); [\/asy]","solution":"336"} +{"question":"The digits of a positive integer $n$ are four consecutive integers in decreasing order when read from left to right. What is the sum of the possible remainders when $n$ is divided by 37?","solution":"217"} +{"question":"Find $c$ if $a$ , $b$ , and $c$ are positive integers which satisfy $c=(a + bi)^3 - 107i$ , where $i^2 = -1$ .","solution":"198"} +{"question":"Two long cylindrical tubes of the same length but different diameters lie parallel to each other on a flat surface . The larger tube has radius $72$ and rolls along the surface toward the smaller tube, which has radius $24$ . It rolls over the smaller tube and continues rolling along the flat surface until it comes to rest on the same point of its circumference as it started, having made one complete revolution. If the smaller tube never moves, and the rolling occurs with no slipping, the larger tube ends up a distance $x$ from where it starts. The distance $x$ can be expressed in the form $a\\pi+b\\sqrt{c},$ where $a,$ $b,$ and $c$ are integers and $c$ is not divisible by the square of any prime . Find $a+b+c.$","solution":"179"} +{"question":"Find $ax^5 + by^5$ if the real numbers $a,b,x,$ and $y$ satisfy the equations \\begin{align*} ax + by &= 3, \\\\ ax^2 + by^2 &= 7, \\\\ ax^3 + by^3 &= 16, \\\\ ax^4 + by^4 &= 42. \\end{align*}","solution":"20"} +{"question":"$ABCD$ is a rectangular sheet of paper that has been folded so that corner $B$ is matched with point $B'$ on edge $AD.$ The crease is $EF,$ where $E$ is on $AB$ and $F$ is on $CD.$ The dimensions $AE=8, BE=17,$ and $CF=3$ are given. The perimeter of rectangle $ABCD$ is $m\/n,$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$ [asy] size(200); defaultpen(linewidth(0.7)+fontsize(10)); pair A=origin, B=(25,0), C=(25,70\/3), D=(0,70\/3), E=(8,0), F=(22,70\/3), Bp=reflect(E,F)*B, Cp=reflect(E,F)*C; draw(F--D--A--E); draw(E--B--C--F, linetype(\"4 4\")); filldraw(E--F--Cp--Bp--cycle, white, black); pair point=( 12.5, 35\/3 ); label(\"$A$\", A, dir(point--A)); label(\"$B$\", B, dir(point--B)); label(\"$C$\", C, dir(point--C)); label(\"$D$\", D, dir(point--D)); label(\"$E$\", E, dir(point--E)); label(\"$F$\", F, dir(point--F)); label(\"$B^\\prime$\", Bp, dir(point--Bp)); label(\"$C^\\prime$\", Cp, dir(point--Cp));[\/asy]","solution":"293"} +{"question":"Find the number of ordered pairs of positive integers $(a,b)$ such that $a+b=1000$ and neither $a$ nor $b$ has a zero digit.","solution":"738"} +{"question":"Let $P$ be the product of the nonreal roots of $x^4-4x^3+6x^2-4x=2005.$ Find $\\lfloor P\\rfloor.$","solution":"45"} +{"question":"In a sequence of coin tosses, one can keep a record of instances in which a tail is immediately followed by a head, a head is immediately followed by a head, and etc. We denote these by TH, HH, and etc. For example, in the sequence TTTHHTHTTTHHTTH of 15 coin tosses we observe that there are two HH, three HT, four TH, and five TT subsequences. How many different sequences of 15 coin tosses will contain exactly two HH, three HT, four TH, and five TT subsequences?","solution":"560"} +{"question":"Two squares of a $7\\times 7$ checkerboard are painted yellow, and the rest are painted green. Two color schemes are equivalent if one can be obtained from the other by applying a rotation in the plane board. How many inequivalent color schemes are possible?","solution":"300"} +{"question":"Given that $x$ and $y$ are both integers between $100$ and $999$ , inclusive; $y$ is the number formed by reversing the digits of $x$ ; and $z=|x-y|$ . How many distinct values of $z$ are possible?","solution":"9"} +{"question":"In triangle $ABC$ , $AB = 125$ , $AC = 117$ , and $BC = 120$ . The angle bisector of angle $A$ intersects $\\overline{BC}$ at point $L$ , and the angle bisector of angle $B$ intersects $\\overline{AC}$ at point $K$ . Let $M$ and $N$ be the feet of the perpendiculars from $C$ to $\\overline{BK}$ and $\\overline{AL}$ , respectively. Find $MN$ .","solution":"56"} +{"question":"Nine delegates, three each from three different countries, randomly select chairs at a round table that seats nine people. Let the probability that each delegate sits next to at least one delegate from another country be $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ . ","solution":"97"} +{"question":"Alpha and Beta both took part in a two-day problem-solving competition. At the end of the second day, each had attempted questions worth a total of $500$ points. Alpha scored $160$ points out of $300$ points attempted on the first day, and scored $140$ points out of $200$ points attempted on the second day. Beta who did not attempt $300$ points on the first day, had a positive integer score on each of the two days, and Beta's daily success rate (points scored divided by points attempted) on each day was less than Alpha's on that day. Alpha's two-day success ratio was $\\frac{300}{500} = \\frac{3}{5}$ . The largest possible two-day success ratio that Beta could achieve is $m\/n,$ where $m$ and $n$ are relatively prime positive integers. What is $m+n$ ?","solution":"849"} +{"question":"Call a permutation $a_1, a_2, \\ldots, a_n$ of the integers $1, 2, \\ldots, n$ quasi-increasing if $a_k \\leq a_{k+1} + 2$ for each $1 \\leq k \\leq n-1$ . For example, $53421$ and $14253$ are quasi-increasing permutations of the integers $1, 2, 3, 4, 5$ , but $45123$ is not. Find the number of quasi-increasing permutations of the integers $1, 2, \\ldots, 7$ .","solution":"486"} +{"question":"Suppose that the sum of the squares of two complex numbers $x$ and $y$ is $7$ and the sum of the cubes is $10$ . What is the largest real value that $x + y$ can have?","solution":"4"} +{"question":"For how many ordered pairs $(x,y)$ of integers is it true that $0 < x < y < 10^{6}$ and that the arithmetic mean of $x$ and $y$ is exactly $2$ more than the geometric mean of $x$ and $y$ ?","solution":"997"} +{"question":"Triangle $AB_0C_0$ has side lengths $AB_0 = 12$ , $B_0C_0 = 17$ , and $C_0A = 25$ . For each positive integer $n$ , points $B_n$ and $C_n$ are located on $\\overline{AB_{n-1}}$ and $\\overline{AC_{n-1}}$ , respectively, creating three similar triangles $\\triangle AB_nC_n \\sim \\triangle B_{n-1}C_nC_{n-1} \\sim \\triangle AB_{n-1}C_{n-1}$ . The area of the union of all triangles $B_{n-1}C_nB_n$ for $n\\geq1$ can be expressed as $\\tfrac pq$ , where $p$ and $q$ are relatively prime positive integers. Find $q$ .","solution":"961"} +{"question":"For any sequence of real numbers $A=(a_1,a_2,a_3,\\ldots)$ , define $\\Delta A^{}_{}$ to be the sequence $(a_2-a_1,a_3-a_2,a_4-a_3,\\ldots)$ , whose $n^{th}$ term is $a_{n+1}-a_n^{}$ . Suppose that all of the terms of the sequence $\\Delta(\\Delta A^{}_{})$ are $1^{}_{}$ , and that $a_{19}=a_{92}^{}=0$ . Find $a_1^{}$ .","solution":"819"} +{"question":"The solutions to the system of equations \\begin{align*} \\log_{225}{x}+\\log_{64}{y} = 4\\\\ \\log_{x}{225}- \\log_{y}{64} = 1 \\end{align*} are $(x_1,y_1)$ and $(x_2, y_2)$ . Find $\\log_{30}{(x_1y_1x_2y_2)}$ .","solution":"12"} +{"question":"What is the largest possible distance between two points, one on the sphere of radius 19 with center $(-2,-10,5),$ and the other on the sphere of radius 87 with center $(12,8,-16)$ ?","solution":"137"} +{"question":"How many real numbers $x^{}_{}$ satisfy the equation $\\frac{1}{5}\\log_2 x = \\sin (5\\pi x)$ ?","solution":"159"} +{"question":"Five men and nine women stand equally spaced around a circle in random order. The probability that every man stands diametrically opposite a woman is $\\frac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$ ","solution":"191"} +{"question":"A transformation of the first quadrant of the coordinate plane maps each point $(x,y)$ to the point $(\\sqrt{x},\\sqrt{y}).$ The vertices of quadrilateral $ABCD$ are $A=(900,300), B=(1800,600), C=(600,1800),$ and $D=(300,900).$ Let $k_{}$ be the area of the region enclosed by the image of quadrilateral $ABCD.$ Find the greatest integer that does not exceed $k_{}.$","solution":"314"} +{"question":"A hexagon is inscribed in a circle. Five of the sides have length 81 and the sixth, denoted by $\\overline{AB}$ , has length 31. Find the sum of the lengths of the three diagonals that can be drawn from $A_{}^{}$ .","solution":"384"} +{"question":"The degree measures of the angles in a convex 18-sided polygon form an increasing arithmetic sequence with integer values. Find the degree measure of the smallest angle.","solution":"143"} +{"question":"Circles $\\omega_1$ and $\\omega_2$ intersect at points $X$ and $Y$ . Line $\\ell$ is tangent to $\\omega_1$ and $\\omega_2$ at $A$ and $B$ , respectively, with line $AB$ closer to point $X$ than to $Y$ . Circle $\\omega$ passes through $A$ and $B$ intersecting $\\omega_1$ again at $D \\neq A$ and intersecting $\\omega_2$ again at $C \\neq B$ . The three points $C$ , $Y$ , $D$ are collinear, $XC = 67$ , $XY = 47$ , and $XD = 37$ . Find $AB^2$ .","solution":"270"} +{"question":"Two real numbers $a$ and $b$ are chosen independently and uniformly at random from the interval $(0, 75)$ . Let $O$ and $P$ be two points on the plane with $OP = 200$ . Let $Q$ and $R$ be on the same side of line $OP$ such that the degree measures of $\\angle POQ$ and $\\angle POR$ are $a$ and $b$ respectively, and $\\angle OQP$ and $\\angle ORP$ are both right angles. The probability that $QR \\leq 100$ is equal to $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"41"} +{"question":"There are positive integers $x$ and $y$ that satisfy the system of equations \\[\\log_{10} x + 2 \\log_{10} (\\gcd(x,y)) = 60\\] \\[\\log_{10} y + 2 \\log_{10} (\\text{lcm}(x,y)) = 570.\\] Let $m$ be the number of (not necessarily distinct) prime factors in the prime factorization of $x$ , and let $n$ be the number of (not necessarily distinct) prime factors in the prime factorization of $y$ . Find $3m+2n$ .","solution":"880"} +{"question":"A positive integer is called ascending if, in its decimal representation, there are at least two digits and each digit is less than any digit to its right. How many ascending positive integers are there? ","solution":"502"} +{"question":"In $\\triangle ABC$ , $AB= 425$ , $BC=450$ , and $AC=510$ . An interior point $P$ is then drawn, and segments are drawn through $P$ parallel to the sides of the triangle. If these three segments are of an equal length $d$ , find $d$ .","solution":"306"} +{"question":"Two three-letter strings, $aaa^{}_{}$ and $bbb^{}_{}$ , are transmitted electronically. Each string is sent letter by letter. Due to faulty equipment, each of the six letters has a 1\/3 chance of being received incorrectly, as an $a^{}_{}$ when it should have been a $b^{}_{}$ , or as a $b^{}_{}$ when it should be an $a^{}_{}$ . However, whether a given letter is received correctly or incorrectly is independent of the reception of any other letter. Let $S_a^{}$ be the three-letter string received when $aaa^{}_{}$ is transmitted and let $S_b^{}$ be the three-letter string received when $bbb^{}_{}$ is transmitted. Let $p$ be the probability that $S_a^{}$ comes before $S_b^{}$ in alphabetical order. When $p$ is written as a fraction in lowest terms, what is its numerator?","solution":"532"} +{"question":"Two dice appear to be normal dice with their faces numbered from $1$ to $6$ , but each die is weighted so that the probability of rolling the number $k$ is directly proportional to $k$ . The probability of rolling a $7$ with this pair of dice is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"71"} +{"question":"Triangle $ABC$ is a right triangle with $AC = 7,$ $BC = 24,$ and right angle at $C.$ Point $M$ is the midpoint of $AB,$ and $D$ is on the same side of line $AB$ as $C$ so that $AD = BD = 15.$ Given that the area of triangle $CDM$ may be expressed as $\\frac {m\\sqrt {n}}{p},$ where $m,$ $n,$ and $p$ are positive integers, $m$ and $p$ are relatively prime, and $n$ is not divisible by the square of any prime, find $m + n + p.$","solution":"578"} +{"question":"For each integer $n\\geq3$ , let $f(n)$ be the number of $3$ -element subsets of the vertices of a regular $n$ -gon that are the vertices of an isosceles triangle (including equilateral triangles). Find the sum of all values of $n$ such that $f(n+1)=f(n)+78$ .","solution":"245"} +{"question":"The diagram shows a rectangle that has been dissected into nine non-overlapping squares. Given that the width and the height of the rectangle are relatively prime positive integers, find the perimeter of the rectangle. [asy]defaultpen(linewidth(0.7)); draw((0,0)--(69,0)--(69,61)--(0,61)--(0,0));draw((36,0)--(36,36)--(0,36)); draw((36,33)--(69,33));draw((41,33)--(41,61));draw((25,36)--(25,61)); draw((34,36)--(34,45)--(25,45)); draw((36,36)--(36,38)--(34,38)); draw((36,38)--(41,38)); draw((34,45)--(41,45));[\/asy]","solution":"260"} +{"question":"Square $AIME$ has sides of length $10$ units. Isosceles triangle $GEM$ has base $EM$ , and the area common to triangle $GEM$ and square $AIME$ is $80$ square units. Find the length of the altitude to $EM$ in $\\triangle GEM$ .","solution":"25"} +{"question":"There exist unique positive integers $x$ and $y$ that satisfy the equation $x^2 + 84x + 2008 = y^2$ . Find $x + y$ .","solution":"80"} +{"question":"Twenty-seven unit cubes are painted orange on a set of four faces so that the two unpainted faces share an edge. The 27 cubes are then randomly arranged to form a $3\\times 3 \\times 3$ cube. Given that the probability that the entire surface of the larger cube is orange is $\\frac{p^a}{q^br^c},$ where $p,q,$ and $r$ are distinct primes and $a,b,$ and $c$ are positive integers, find $a+b+c+p+q+r.$","solution":"74"} +{"question":"In $\\triangle ABC$ let $I$ be the center of the inscribed circle, and let the bisector of $\\angle ACB$ intersect $\\overline{AB}$ at $L$ . The line through $C$ and $L$ intersects the circumscribed circle of $\\triangle ABC$ at the two points $C$ and $D$ . If $LI=2$ and $LD=3$ , then $IC= \\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"13"} +{"question":"Let $\\mathcal{S}$ be the set of all perfect squares whose rightmost three digits in base $10$ are $256$ . Let $\\mathcal{T}$ be the set of all numbers of the form $\\frac{x-256}{1000}$ , where $x$ is in $\\mathcal{S}$ . In other words, $\\mathcal{T}$ is the set of numbers that result when the last three digits of each number in $\\mathcal{S}$ are truncated. Find the remainder when the tenth smallest element of $\\mathcal{T}$ is divided by $1000$ .","solution":"170"} +{"question":"For how many real numbers $a^{}_{}$ does the quadratic equation $x^2 + ax^{}_{} + 6a=0$ have only integer roots for $x^{}_{}$ ?","solution":"10"} +{"question":"In the expansion of $(ax + b)^{2000},$ where $a$ and $b$ are relatively prime positive integers, the coefficients of $x^{2}$ and $x^{3}$ are equal. Find $a + b$ .","solution":"667"} +{"question":"A $7\\times 1$ board is completely covered by $m\\times 1$ tiles without overlap; each tile may cover any number of consecutive squares, and each tile lies completely on the board. Each tile is either red, blue, or green. Let $N$ be the number of tilings of the $7\\times 1$ board in which all three colors are used at least once. For example, a $1\\times 1$ red tile followed by a $2\\times 1$ green tile, a $1\\times 1$ green tile, a $2\\times 1$ blue tile, and a $1\\times 1$ green tile is a valid tiling. Note that if the $2\\times 1$ blue tile is replaced by two $1\\times 1$ blue tiles, this results in a different tiling. Find the remainder when $N$ is divided by $1000$ .","solution":"106"} +{"question":"Let the set $\\mathcal{S} = \\{8, 5, 1, 13, 34, 3, 21, 2\\}.$ Susan makes a list as follows: for each two-element subset of $\\mathcal{S},$ she writes on her list the greater of the set's two elements. Find the sum of the numbers on the list.","solution":"484"} +{"question":"Find the arithmetic mean of all the three-digit palindromes. (Recall that a palindrome is a number that reads the same forward and backward, such as $777$ or $383$ .)","solution":"550"} +{"question":"The value of $x$ that satisfies $\\log_{2^x} 3^{20} = \\log_{2^{x+3}} 3^{2020}$ can be written as $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"103"} +{"question":"Find the number of positive integers $m$ for which there exist nonnegative integers $x_0$ , $x_1$ , $\\dots$ , $x_{2011}$ such that \\[m^{x_0} = \\sum_{k = 1}^{2011} m^{x_k}.\\]","solution":"16"} +{"question":"Let $\\mathcal{S}$ be the set $\\lbrace1,2,3,\\ldots,10\\rbrace$ Let $n$ be the number of sets of two non-empty disjoint subsets of $\\mathcal{S}$ . (Disjoint sets are defined as sets that have no common elements.) Find the remainder obtained when $n$ is divided by $1000$ .","solution":"501"} +{"question":"Let $u$ and $v$ be integers satisfying $0 < v < u$ . Let $A = (u,v)$ , let $B$ be the reflection of $A$ across the line $y = x$ , let $C$ be the reflection of $B$ across the y-axis, let $D$ be the reflection of $C$ across the x-axis, and let $E$ be the reflection of $D$ across the y-axis. The area of pentagon $ABCDE$ is $451$ . Find $u + v$ .","solution":"21"} +{"question":"Let $S$ be the set of integers between 1 and $2^{40}$ whose binary expansions have exactly two 1's. If a number is chosen at random from $S,$ the probability that it is divisible by 9 is $p\/q,$ where $p$ and $q$ are relatively prime positive integers. Find $p+q.$","solution":"913"} +{"question":"Alice knows that $3$ red cards and $3$ black cards will be revealed to her one at a time in random order. Before each card is revealed, Alice must guess its color. If Alice plays optimally, the expected number of cards she will guess correctly is $\\frac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$","solution":"51"} +{"question":"Circles $C_1$ and $C_2$ are externally tangent, and they are both internally tangent to circle $C_3.$ The radii of $C_1$ and $C_2$ are 4 and 10, respectively, and the centers of the three circles are all collinear. A chord of $C_3$ is also a common external tangent of $C_1$ and $C_2.$ Given that the length of the chord is $\\frac{m\\sqrt{n}}p$ where $m,n,$ and $p$ are positive integers, $m$ and $p$ are relatively prime, and $n$ is not divisible by the square of any prime, find $m+n+p.$","solution":"405"} +{"question":"Find the least positive integer such that when its leftmost digit is deleted, the resulting integer is $1\/29$ of the original integer.","solution":"725"} +{"question":"In parallelogram $ABCD,$ let $O$ be the intersection of diagonals $\\overline{AC}$ and $\\overline{BD}$ . Angles $CAB$ and $DBC$ are each twice as large as angle $DBA,$ and angle $ACB$ is $r$ times as large as angle $AOB$ . Find the greatest integer that does not exceed $1000r$ .","solution":"777"} +{"question":"A set $\\mathcal{S}$ of distinct positive integers has the following property: for every integer $x$ in $\\mathcal{S},$ the arithmetic mean of the set of values obtained by deleting $x$ from $\\mathcal{S}$ is an integer. Given that 1 belongs to $\\mathcal{S}$ and that 2002 is the largest element of $\\mathcal{S},$ what is the greatest number of elements that $\\mathcal{S}$ can have?","solution":"30"} +{"question":"Compute $\\sqrt{(31)(30)(29)(28)+1}$ .","solution":"869"} +{"question":"The numbers in the sequence $101$ , $104$ , $109$ , $116$ , $\\ldots$ are of the form $a_n=100+n^2$ , where $n=1,2,3,\\ldots$ . For each $n$ , let $d_n$ be the greatest common divisor of $a_n$ and $a_{n+1}$ . Find the maximum value of $d_n$ as $n$ ranges through the positive integers .","solution":"401"} +{"question":"Let $P$ be a point chosen uniformly at random in the interior of the unit square with vertices at $(0,0), (1,0), (1,1)$ , and $(0,1)$ . The probability that the slope of the line determined by $P$ and the point $\\left(\\frac58, \\frac38 \\right)$ is greater than or equal to $\\frac12$ can be written as $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"171"} +{"question":"For $n\\ge1$ call a finite sequence $(a_1,a_2,\\ldots,a_n)$ of positive integers progressive if $a_i CP$ . Let $O_1$ and $O_2$ be the circumcenters of triangles $ABP$ and $CDP$ , respectively. Given that $AB = 12$ and $\\angle O_1PO_2 = 120 ^{\\circ}$ , then $AP = \\sqrt{a} + \\sqrt{b}$ , where $a$ and $b$ are positive integers. Find $a + b$ .","solution":"96"} +{"question":"For any positive integer $x_{}$ , let $S(x)$ be the sum of the digits of $x_{}$ , and let $T(x)$ be $|S(x+2)-S(x)|.$ For example, $T(199)=|S(201)-S(199)|=|3-19|=16.$ How many values of $T(x)$ do not exceed 1999?","solution":"223"} +{"question":"Let $ABCD$ be a convex quadrilateral with $AB = CD = 10$ , $BC = 14$ , and $AD = 2\\sqrt{65}$ . Assume that the diagonals of $ABCD$ intersect at point $P$ , and that the sum of the areas of triangles $APB$ and $CPD$ equals the sum of the areas of triangles $BPC$ and $APD$ . Find the area of quadrilateral $ABCD$ .","solution":"112"} +{"question":"In a certain circle, the chord of a $d$ -degree arc is 22 centimeters long, and the chord of a $2d$ -degree arc is 20 centimeters longer than the chord of a $3d$ -degree arc, where $d < 120.$ The length of the chord of a $3d$ -degree arc is $- m + \\sqrt {n}$ centimeters, where $m$ and $n$ are positive integers. Find $m + n.$","solution":"174"} +{"question":"Point $B$ lies on line segment $\\overline{AC}$ with $AB=16$ and $BC=4$ . Points $D$ and $E$ lie on the same side of line $AC$ forming equilateral triangles $\\triangle ABD$ and $\\triangle BCE$ . Let $M$ be the midpoint of $\\overline{AE}$ , and $N$ be the midpoint of $\\overline{CD}$ . The area of $\\triangle BMN$ is $x$ . Find $x^2$ .","solution":"507"} +{"question":"Define a $\\text{good word}$ as a sequence of letters that consists only of the letters $A$ , $B$ , and $C$ - some of these letters may not appear in the sequence - and in which $A$ is never immediately followed by $B$ , $B$ is never immediately followed by $C$ , and $C$ is never immediately followed by $A$ . How many seven-letter good words are there? ","solution":"192"} +{"question":"A circle with diameter $\\overline{PQ}\\,$ of length 10 is internally tangent at $P^{}_{}$ to a circle of radius 20. Square $ABCD\\,$ is constructed with $A\\,$ and $B\\,$ on the larger circle, $\\overline{CD}\\,$ tangent at $Q\\,$ to the smaller circle, and the smaller circle outside $ABCD\\,$ . The length of $\\overline{AB}\\,$ can be written in the form $m + \\sqrt{n}\\,$ , where $m\\,$ and $n\\,$ are integers. Find $m + n\\,$ .","solution":"312"} +{"question":"The perimeter of triangle $APM$ is $152$ , and the angle $PAM$ is a right angle. A circle of radius $19$ with center $O$ on $\\overline{AP}$ is drawn so that it is tangent to $\\overline{AM}$ and $\\overline{PM}$ . Given that $OP=m\/n$ where $m$ and $n$ are relatively prime positive integers, find $m+n$ .","solution":"98"} +{"question":"Point $P_{}$ is located inside triangle $ABC$ so that angles $PAB, PBC,$ and $PCA$ are all congruent. The sides of the triangle have lengths $AB=13, BC=14,$ and $CA=15,$ and the tangent of angle $PAB$ is $m\/n,$ where $m_{}$ and $n_{}$ are relatively prime positive integers. Find $m+n.$","solution":"463"} +{"question":"Suppose that the roots of $x^3+3x^2+4x-11=0$ are $a$ , $b$ , and $c$ , and that the roots of $x^3+rx^2+sx+t=0$ are $a+b$ , $b+c$ , and $c+a$ . Find $t$ .","solution":"23"} +{"question":"Let $a_{10} = 10$ , and for each positive integer $n >10$ let $a_n = 100a_{n - 1} + n$ . Find the least positive $n > 10$ such that $a_n$ is a multiple of $99$ .","solution":"45"} +{"question":"Let $S$ be the set of all polynomials of the form $z^3 + az^2 + bz + c$ , where $a$ , $b$ , and $c$ are integers. Find the number of polynomials in $S$ such that each of its roots $z$ satisfies either $|z| = 20$ or $|z| = 13$ .","solution":"540"} +{"question":"Misha rolls a standard, fair six-sided die until she rolls 1-2-3 in that order on three consecutive rolls. The probability that she will roll the die an odd number of times is $\\dfrac{m}{n}$ where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"647"} +{"question":"When each of $702$ , $787$ , and $855$ is divided by the positive integer $m$ , the remainder is always the positive integer $r$ . When each of $412$ , $722$ , and $815$ is divided by the positive integer $n$ , the remainder is always the positive integer $s \\neq r$ . Find $m+n+r+s$ .","solution":"62"} +{"question":"For distinct complex numbers $z_1,z_2,\\dots,z_{673}$ , the polynomial \\[(x-z_1)^3(x-z_2)^3 \\cdots (x-z_{673})^3\\] can be expressed as $x^{2019} + 20x^{2018} + 19x^{2017}+g(x)$ , where $g(x)$ is a polynomial with complex coefficients and with degree at most $2016$ . The value of \\[\\left| \\sum_{1 \\le j 0$ . Find the base- $10$ representation of $n$ .","solution":"925"} +{"question":"Two distinct, real, infinite geometric series each have a sum of $1$ and have the same second term. The third term of one of the series is $1\/8$ , and the second term of both series can be written in the form $\\frac{\\sqrt{m}-n}p$ , where $m$ , $n$ , and $p$ are positive integers and $m$ is not divisible by the square of any prime. Find $100m+10n+p$ .","solution":"518"} +{"question":"What is that largest positive integer $n$ for which $n^3+100$ is divisible by $n+10$ ?","solution":"890"} +{"question":"Dave arrives at an airport which has twelve gates arranged in a straight line with exactly $100$ feet between adjacent gates. His departure gate is assigned at random. After waiting at that gate, Dave is told the departure gate has been changed to a different gate, again at random. Let the probability that Dave walks $400$ feet or less to the new gate be a fraction $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"52"} +{"question":"Let $\\overline{MN}$ be a diameter of a circle with diameter $1$ . Let $A$ and $B$ be points on one of the semicircular arcs determined by $\\overline{MN}$ such that $A$ is the midpoint of the semicircle and $MB=\\dfrac 35$ . Point $C$ lies on the other semicircular arc. Let $d$ be the length of the line segment whose endpoints are the intersections of diameter $\\overline{MN}$ with the chords $\\overline{AC}$ and $\\overline{BC}$ . The largest possible value of $d$ can be written in the form $r-s\\sqrt t$ , where $r$ , $s$ , and $t$ are positive integers and $t$ is not divisible by the square of any prime. Find $r+s+t$ .","solution":"14"} +{"question":"Let $\\triangle ABC$ be a right triangle with right angle at $C.$ Let $D$ and $E$ be points on $\\overline{AB}$ with $D$ between $A$ and $E$ such that $\\overline{CD}$ and $\\overline{CE}$ trisect $\\angle C.$ If $\\frac{DE}{BE} = \\frac{8}{15},$ then $\\tan B$ can be written as $\\frac{m \\sqrt{p}}{n},$ where $m$ and $n$ are relatively prime positive integers, and $p$ is a positive integer not divisible by the square of any prime. Find $m+n+p.$","solution":"18"} +{"question":"Let $R$ be the set of all possible remainders when a number of the form $2^n$ , $n$ a nonnegative integer, is divided by 1000. Let $S$ be the sum of the elements in $R$ . Find the remainder when $S$ is divided by 1000.","solution":"7"} +{"question":"Euler's formula states that for a convex polyhedron with $V\\,$ vertices, $E\\,$ edges, and $F\\,$ faces, $V-E+F=2\\,$ . A particular convex polyhedron has 32 faces, each of which is either a triangle or a pentagon. At each of its $V\\,$ vertices, $T\\,$ triangular faces and $P^{}_{}$ pentagonal faces meet. What is the value of $100P+10T+V\\,$ ?","solution":"250"} +{"question":"A small square is constructed inside a square of area $1$ by dividing each side of the unit square into $n$ equal parts, and then connecting the vertices to the division points closest to the opposite vertices, as shown in the figure. Find the value of $n$ if the the area of the small square is exactly $\\frac1{1985}$ . AIME 1985 Problem 4.png","solution":"32"} +{"question":"Let $a = \\pi\/2008$ . Find the smallest positive integer $n$ such that \\[2[\\cos(a)\\sin(a) + \\cos(4a)\\sin(2a) + \\cos(9a)\\sin(3a) + \\cdots + \\cos(n^2a)\\sin(na)]\\] is an integer.","solution":"251"} +{"question":"The increasing sequence $1,3,4,9,10,12,13\\cdots$ consists of all those positive integers which are powers of 3 or sums of distinct powers of 3. Find the $100^{\\mbox{th}}$ term of this sequence.","solution":"981"} +{"question":"For certain real values of $a, b, c,$ and $d_{},$ the equation $x^4+ax^3+bx^2+cx+d=0$ has four non-real roots. The product of two of these roots is $13+i$ and the sum of the other two roots is $3+4i,$ where $i=\\sqrt{-1}.$ Find $b.$","solution":"51"} +{"question":"The positive integers $N$ and $N^2$ both end in the same sequence of four digits $abcd$ when written in base 10, where digit $a$ is not zero. Find the three-digit number $abc$ .","solution":"937"} +{"question":"Find the number of ordered pairs $(x,y)$ of positive integers that satisfy $x \\le 2y \\le 60$ and $y \\le 2x \\le 60$ .","solution":"480"} +{"question":"Let $x$ , $y$ and $z$ all exceed $1$ and let $w$ be a positive number such that $\\log_xw=24$ , $\\log_y w = 40$ and $\\log_{xyz}w=12$ . Find $\\log_zw$ .","solution":"60"} +{"question":"Let $m$ be a positive integer, and let $a_0, a_1,\\ldots,a_m$ be a sequence of reals such that $a_0 = 37, a_1 = 72, a_m = 0,$ and $a_{k+1} = a_{k-1} - \\frac 3{a_k}$ for $k = 1,2,\\ldots, m-1.$ Find $m.$","solution":"889"} +{"question":"The equation $2000x^6+100x^5+10x^3+x-2=0$ has exactly two real roots, one of which is $\\frac{m+\\sqrt{n}}r$ , where $m$ , $n$ and $r$ are integers, $m$ and $r$ are relatively prime, and $r>0$ . Find $m+n+r$ .","solution":"200"} +{"question":"Let $P(x)$ be a polynomial with integer coefficients that satisfies $P(17)=10$ and $P(24)=17.$ Given that $P(n)=n+3$ has two distinct integer solutions $n_1$ and $n_2,$ find the product $n_1\\cdot n_2.$","solution":"418"} +{"question":"A rectangle that is inscribed in a larger rectangle (with one vertex on each side) is called unstuck if it is possible to rotate (however slightly) the smaller rectangle about its center within the confines of the larger. Of all the rectangles that can be inscribed unstuck in a 6 by 8 rectangle, the smallest perimeter has the form $\\sqrt{N}\\,$ , for a positive integer $N\\,$ . Find $N\\,$ .","solution":"448"} +{"question":"In triangle $ABC$ , $AB = AC = 100$ , and $BC = 56$ . Circle $P$ has radius $16$ and is tangent to $\\overline{AC}$ and $\\overline{BC}$ . Circle $Q$ is externally tangent to circle $P$ and is tangent to $\\overline{AB}$ and $\\overline{BC}$ . No point of circle $Q$ lies outside of $\\bigtriangleup\\overline{ABC}$ . The radius of circle $Q$ can be expressed in the form $m - n\\sqrt{k}$ ,where $m$ , $n$ , and $k$ are positive integers and $k$ is the product of distinct primes. Find $m +nk$ .","solution":"254"} +{"question":"Let $\\overline{CH}$ be an altitude of $\\triangle ABC$ . Let $R\\,$ and $S\\,$ be the points where the circles inscribed in the triangles $ACH\\,$ and $BCH^{}_{}$ are tangent to $\\overline{CH}$ . If $AB = 1995\\,$ , $AC = 1994\\,$ , and $BC = 1993\\,$ , then $RS\\,$ can be expressed as $m\/n\\,$ , where $m\\,$ and $n\\,$ are relatively prime integers. Find $m + n\\,$ .","solution":"997"} +{"question":"During a recent campaign for office, a candidate made a tour of a country which we assume lies in a plane. On the first day of the tour he went east, on the second day he went north, on the third day west, on the fourth day south, on the fifth day east, etc. If the candidate went $\\frac{n^{2}}{2}$ miles on the $n^{\\mbox{th}}_{}$ day of this tour, how many miles was he from his starting point at the end of the $40^{\\mbox{th}}_{}$ day?","solution":"580"} +{"question":"Find the least positive integer $n$ such that no matter how $10^{n}$ is expressed as the product of any two positive integers, at least one of these two integers contains the digit $0$ .","solution":"8"} +{"question":"For each real number $x$ , let $\\lfloor x \\rfloor$ denote the greatest integer that does not exceed $x$ . For how many positive integers $n$ is it true that $n<1000$ and that $\\lfloor \\log_{2} n \\rfloor$ is a positive even integer?","solution":"340"} +{"question":"Abe can paint the room in 15 hours, Bea can paint 50 percent faster than Abe, and Coe can paint twice as fast as Abe. Abe begins to paint the room and works alone for the first hour and a half. Then Bea joins Abe, and they work together until half the room is painted. Then Coe joins Abe and Bea, and they work together until the entire room is painted. Find the number of minutes after Abe begins for the three of them to finish painting the room.","solution":"334"} +{"question":"The shortest distances between an interior diagonal of a rectangular parallelepiped , $P$ , and the edges it does not meet are $2\\sqrt{5}$ , $\\frac{30}{\\sqrt{13}}$ , and $\\frac{15}{\\sqrt{10}}$ . Determine the volume of $P$ .","solution":"750"} +{"question":"A chord of a circle is perpendicular to a radius at the midpoint of the radius. The ratio of the area of the larger of the two regions into which the chord divides the circle to the smaller can be expressed in the form $\\frac{a\\pi+b\\sqrt{c}}{d\\pi-e\\sqrt{f}},$ where $a, b, c, d, e,$ and $f$ are positive integers, $a$ and $e$ are relatively prime, and neither $c$ nor $f$ is divisible by the square of any prime. Find the remainder when the product $abcdef$ is divided by 1000.","solution":"592"} +{"question":"Compute \\[\\frac{(10^4+324)(22^4+324)(34^4+324)(46^4+324)(58^4+324)}{(4^4+324)(16^4+324)(28^4+324)(40^4+324)(52^4+324)}.\\]","solution":"373"} +{"question":"Let $N = 100^2 + 99^2 - 98^2 - 97^2 + 96^2 + \\cdots + 4^2 + 3^2 - 2^2 - 1^2$ , where the additions and subtractions alternate in pairs. Find the remainder when $N$ is divided by $1000$ .","solution":"100"} +{"question":"One base of a trapezoid is $100$ units longer than the other base. The segment that joins the midpoints of the legs divides the trapezoid into two regions whose areas are in the ratio $2: 3$ . Let $x$ be the length of the segment joining the legs of the trapezoid that is parallel to the bases and that divides the trapezoid into two regions of equal area. Find the greatest integer that does not exceed $x^2\/100$ .","solution":"181"} +{"question":"Find the number of ordered pairs of positive integer solutions $(m, n)$ to the equation $20m + 12n = 2012$ .","solution":"34"} +{"question":"The terms of an arithmetic sequence add to $715$ . The first term of the sequence is increased by $1$ , the second term is increased by $3$ , the third term is increased by $5$ , and in general, the $k$ th term is increased by the $k$ th odd positive integer. The terms of the new sequence add to $836$ . Find the sum of the first, last, and middle term of the original sequence.","solution":"195"} +{"question":"Find $a$ if $a$ and $b$ are integers such that $x^2 - x - 1$ is a factor of $ax^{17} + bx^{16} + 1$ .","solution":"987"} +{"question":"Let $L$ be the line with slope $\\frac{5}{12}$ that contains the point $A = (24,-1)$ , and let $M$ be the line perpendicular to line $L$ that contains the point $B = (5,6)$ . The original coordinate axes are erased, and line $L$ is made the $x$ -axis and line $M$ the $y$ -axis. In the new coordinate system, point $A$ is on the positive $x$ -axis, and point $B$ is on the positive $y$ -axis. The point $P$ with coordinates $(-14,27)$ in the original system has coordinates $(\\alpha,\\beta)$ in the new coordinate system. Find $\\alpha + \\beta$ .","solution":"31"} +{"question":"By a proper divisor of a natural number we mean a positive integral divisor other than 1 and the number itself. A natural number greater than 1 will be called \"nice\" if it is equal to the product of its distinct proper divisors. What is the sum of the first ten nice numbers?","solution":"182"} +{"question":"A cube with side length 10 is suspended above a plane. The vertex closest to the plane is labeled $A$ . The three vertices adjacent to vertex $A$ are at heights 10, 11, and 12 above the plane. The distance from vertex $A$ to the plane can be expressed as $\\frac{r - \\sqrt{s}}{t}$ , where $r$ , $s$ , and $t$ are positive integers. Find $r + s + t$ .","solution":"330"} +{"question":"Let $w$ and $z$ be complex numbers such that $|w| = 1$ and $|z| = 10$ . Let $\\theta = \\arg \\left(\\tfrac{w-z}{z}\\right)$ . The maximum possible value of $\\tan^2 \\theta$ can be written as $\\tfrac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ . (Note that $\\arg(w)$ , for $w \\neq 0$ , denotes the measure of the angle that the ray from $0$ to $w$ makes with the positive real axis in the complex plane.)","solution":"100"} +{"question":"In the Cartesian plane let $A = (1,0)$ and $B = \\left( 2, 2\\sqrt{3} \\right)$ . Equilateral triangle $ABC$ is constructed so that $C$ lies in the first quadrant. Let $P=(x,y)$ be the center of $\\triangle ABC$ . Then $x \\cdot y$ can be written as $\\tfrac{p\\sqrt{q}}{r}$ , where $p$ and $r$ are relatively prime positive integers and $q$ is an integer that is not divisible by the square of any prime. Find $p+q+r$ .","solution":"40"} +{"question":"Let $ABCD$ be an isosceles trapezoid, whose dimensions are $AB = 6, BC=5=DA,$ and $CD=4.$ Draw circles of radius 3 centered at $A$ and $B$ and circles of radius 2 centered at $C$ and $D.$ A circle contained within the trapezoid is tangent to all four of these circles. Its radius is $\\frac{-k+m\\sqrt{n}}p,$ where $k, m, n,$ and $p$ are positive integers, $n$ is not divisible by the square of any prime, and $k$ and $p$ are relatively prime. Find $k+m+n+p.$","solution":"134"} +{"question":"There are real numbers $a, b, c,$ and $d$ such that $-20$ is a root of $x^3 + ax + b$ and $-21$ is a root of $x^3 + cx^2 + d.$ These two polynomials share a complex root $m + \\sqrt{n} \\cdot i,$ where $m$ and $n$ are positive integers and $i = \\sqrt{-1}.$ Find $m+n.$","solution":"330"} +{"question":"Let $\\mathcal{R}$ be the region consisting of the set of points in the coordinate plane that satisfy both $|8 - x| + y \\le 10$ and $3y - x \\ge 15$ . When $\\mathcal{R}$ is revolved around the line whose equation is $3y - x = 15$ , the volume of the resulting solid is $\\frac {m\\pi}{n\\sqrt {p}}$ , where $m$ , $n$ , and $p$ are positive integers, $m$ and $n$ are relatively prime, and $p$ is not divisible by the square of any prime. Find $m + n + p$ .","solution":"365"} +{"question":"A game show offers a contestant three prizes A, B and C, each of which is worth a whole number of dollars from $\\text{\\textdollar}1$ to $\\text{\\textdollar}9999$ inclusive. The contestant wins the prizes by correctly guessing the price of each prize in the order A, B, C. As a hint, the digits of the three prices are given. On a particular day, the digits given were $1, 1, 1, 1, 3, 3, 3$ . Find the total number of possible guesses for all three prizes consistent with the hint.","solution":"420"} +{"question":"Regular octagon $A_1A_2A_3A_4A_5A_6A_7A_8$ is inscribed in a circle of area $1.$ Point $P$ lies inside the circle so that the region bounded by $\\overline{PA_1},\\overline{PA_2},$ and the minor arc $\\widehat{A_1A_2}$ of the circle has area $\\tfrac{1}{7},$ while the region bounded by $\\overline{PA_3},\\overline{PA_4},$ and the minor arc $\\widehat{A_3A_4}$ of the circle has area $\\tfrac{1}{9}.$ There is a positive integer $n$ such that the area of the region bounded by $\\overline{PA_6},\\overline{PA_7},$ and the minor arc $\\widehat{A_6A_7}$ of the circle is equal to $\\tfrac{1}{8}-\\tfrac{\\sqrt2}{n}.$ Find $n.$","solution":"504"} +{"question":"Kathy has $5$ red cards and $5$ green cards. She shuffles the $10$ cards and lays out $5$ of the cards in a row in a random order. She will be happy if and only if all the red cards laid out are adjacent and all the green cards laid out are adjacent. For example, card orders RRGGG, GGGGR, or RRRRR will make Kathy happy, but RRRGR will not. The probability that Kathy will be happy is $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"157"} +{"question":"There are two distinguishable flagpoles, and there are $19$ flags, of which $10$ are identical blue flags, and $9$ are identical green flags. Let $N$ be the number of distinguishable arrangements using all of the flags in which each flagpole has at least one flag and no two green flags on either pole are adjacent. Find the remainder when $N$ is divided by $1000$ .","solution":"310"} +{"question":"Call a positive integer $n$ extra-distinct if the remainders when $n$ is divided by $2, 3, 4, 5,$ and $6$ are distinct. Find the number of extra-distinct positive integers less than $1000$ .","solution":"49"} +{"question":"How many even integers between 4000 and 7000 have four different digits?","solution":"728"} +{"question":"Given a function $f$ for which \\[f(x) = f(398 - x) = f(2158 - x) = f(3214 - x)\\] holds for all real $x,$ what is the largest number of different values that can appear in the list $f(0),f(1),f(2),\\ldots,f(999)$ ?","solution":"177"} +{"question":"Consider a string of $n$ $7$ 's, $7777\\cdots77,$ into which $+$ signs are inserted to produce an arithmetic expression. For example, $7+77+777+7+7=875$ could be obtained from eight $7$ 's in this way. For how many values of $n$ is it possible to insert $+$ signs so that the resulting expression has value $7000$ ?","solution":"108"} +{"question":"Given that $z$ is a complex number such that $z+\\frac 1z=2\\cos 3^\\circ$ , find the least integer that is greater than $z^{2000}+\\frac 1{z^{2000}}$ .","solution":"0"} +{"question":"Consider the set of all triangles $OPQ$ where $O$ is the origin and $P$ and $Q$ are distinct points in the plane with nonnegative integer coordinates $(x,y)$ such that $41x + y = 2009$ . Find the number of such distinct triangles whose area is a positive integer.","solution":"600"} +{"question":"The terms of the sequence $\\{a_i\\}$ defined by $a_{n + 2} = \\frac {a_n + 2009} {1 + a_{n + 1}}$ for $n \\ge 1$ are positive integers. Find the minimum possible value of $a_1 + a_2$ .","solution":"90"} +{"question":"How many positive integers less than 10,000 have at most two different digits?","solution":"927"} +{"question":"Mary told John her score on the American High School Mathematics Examination (AHSME), which was over $80$ . From this, John was able to determine the number of problems Mary solved correctly. If Mary's score had been any lower, but still over $80$ , John could not have determined this. What was Mary's score? (Recall that the AHSME consists of $30$ multiple choice problems and that one's score, $s$ , is computed by the formula $s=30+4c-w$ , where $c$ is the number of correct answers and $w$ is the number of wrong answers. Students are not penalized for problems left unanswered.)","solution":"119"} +{"question":"Let $m$ be the smallest integer whose cube root is of the form $n+r$ , where $n$ is a positive integer and $r$ is a positive real number less than $1\/1000$ . Find $n$ .","solution":"19"} +{"question":"Recall that a palindrome is a number that reads the same forward and backward. Find the greatest integer less than $1000$ that is a palindrome both when written in base ten and when written in base eight, such as $292 = 444_{\\text{eight}}.$","solution":"585"} +{"question":"The increasing geometric sequence $x_{0},x_{1},x_{2},\\ldots$ consists entirely of integral powers of $3.$ Given that $\\sum_{n=0}^{7}\\log_{3}(x_{n}) = 308$ and $56 \\leq \\log_{3}\\left ( \\sum_{n=0}^{7}x_{n}\\right ) \\leq 57,$ find $\\log_{3}(x_{14}).$","solution":"91"} +{"question":"Let $N$ be the greatest integer multiple of 8, whose digits are all different. What is the remainder when $N$ is divided by 1000?","solution":"120"} +{"question":"Twenty five of King Arthur's knights are seated at their customary round table. Three of them are chosen - all choices being equally likely - and are sent off to slay a troublesome dragon. Let $P$ be the probability that at least two of the three had been sitting next to each other. If $P$ is written as a fraction in lowest terms, what is the sum of the numerator and denominator? ","solution":"57"} +{"question":"For any integer $k\\geq 1$ , let $p(k)$ be the smallest prime which does not divide $k$ . Define the integer function $X(k)$ to be the product of all primes less than $p(k)$ if $p(k)>2$ , and $X(k)=1$ if $p(k)=2$ . Let $\\{x_n\\}$ be the sequence defined by $x_0=1$ , and $x_{n+1}X(x_n)=x_np(x_n)$ for $n\\geq 0$ . Find the smallest positive integer $t$ such that $x_t=2090$ .","solution":"149"} +{"question":"A triangular array of squares has one square in the first row, two in the second, and in general, $k$ squares in the $k$ th row for $1 \\leq k \\leq 11.$ With the exception of the bottom row, each square rests on two squares in the row immediately below (illustrated in given diagram). In each square of the eleventh row, a $0$ or a $1$ is placed. Numbers are then placed into the other squares, with the entry for each square being the sum of the entries in the two squares below it. For how many initial distributions of $0$ 's and $1$ 's in the bottom row is the number in the top square a multiple of $3$ ? [asy] for (int i=0; i<12; ++i){ for (int j=0; ja_{i+1}$ if $i$ is even. How many snakelike integers between 1000 and 9999 have four distinct digits?","solution":"882"} +{"question":"Let $m \\ge 3$ be an integer and let $S = \\{3,4,5,\\ldots,m\\}$ . Find the smallest value of $m$ such that for every partition of $S$ into two subsets, at least one of the subsets contains integers $a$ , $b$ , and $c$ (not necessarily distinct) such that $ab = c$ . Note : a partition of $S$ is a pair of sets $A$ , $B$ such that $A \\cap B = \\emptyset$ , $A \\cup B = S$ .","solution":"243"} +{"question":"The function $f$ , defined on the set of ordered pairs of positive integers, satisfies the following properties: \\[f(x, x) = x,\\; f(x, y) = f(y, x), {\\rm \\ and\\ } (x+y)f(x, y) = yf(x, x+y).\\] Calculate $f(14,52)$ .","solution":"364"} +{"question":"For every $m \\geq 2$ , let $Q(m)$ be the least positive integer with the following property: For every $n \\geq Q(m)$ , there is always a perfect cube $k^3$ in the range $n < k^3 \\leq mn$ . Find the remainder when \\[\\sum_{m = 2}^{2017} Q(m)\\] is divided by $1000$ .","solution":"59"} +{"question":"Let $\\mathcal{S}$ be the set of real numbers that can be represented as repeating decimals of the form $0.\\overline{abc}$ where $a, b, c$ are distinct digits. Find the sum of the elements of $\\mathcal{S}.$","solution":"360"} +{"question":"Twelve congruent disks are placed on a circle $C^{}_{}$ of radius 1 in such a way that the twelve disks cover $C^{}_{}$ , no two of the disks overlap, and so that each of the twelve disks is tangent to its two neighbors. The resulting arrangement of disks is shown in the figure below. The sum of the areas of the twelve disks can be written in the form $\\pi(a-b\\sqrt{c})$ , where $a,b,c^{}_{}$ are positive integers and $c^{}_{}$ is not divisible by the square of any prime. Find $a+b+c^{}_{}$ . [asy] unitsize(100); draw(Circle((0,0),1)); dot((0,0)); draw((0,0)--(1,0)); label(\"$1$\", (0.5,0), S); for (int i=0; i<12; ++i) { dot((cos(i*pi\/6), sin(i*pi\/6))); } for (int a=1; a<24; a+=2) { dot(((1\/cos(pi\/12))*cos(a*pi\/12), (1\/cos(pi\/12))*sin(a*pi\/12))); draw(((1\/cos(pi\/12))*cos(a*pi\/12), (1\/cos(pi\/12))*sin(a*pi\/12))--((1\/cos(pi\/12))*cos((a+2)*pi\/12), (1\/cos(pi\/12))*sin((a+2)*pi\/12))); draw(Circle(((1\/cos(pi\/12))*cos(a*pi\/12), (1\/cos(pi\/12))*sin(a*pi\/12)), tan(pi\/12))); } [\/asy]","solution":"135"} +{"question":"Find the smallest positive integer $n$ for which the expansion of $(xy-3x+7y-21)^n$ , after like terms have been collected, has at least 1996 terms.","solution":"44"} +{"question":"Find the least positive integer $k$ for which the equation $\\left\\lfloor\\frac{2002}{n}\\right\\rfloor=k$ has no integer solutions for $n$ . (The notation $\\lfloor x\\rfloor$ means the greatest integer less than or equal to $x$ .)","solution":"49"} +{"question":"Find the smallest prime that is the fifth term of an increasing arithmetic sequence, all four preceding terms also being prime. ","solution":"29"} +{"question":"Let $N$ be the largest positive integer with the following property: reading from left to right, each pair of consecutive digits of $N$ forms a perfect square. What are the leftmost three digits of $N$ ? ","solution":"816"} +{"question":"Consider the paper triangle whose vertices are $(0,0), (34,0),$ and $(16,24).$ The vertices of its midpoint triangle are the midpoints of its sides. A triangular pyramid is formed by folding the triangle along the sides of its midpoint triangle. What is the volume of this pyramid?","solution":"408"} +{"question":"Consider all 1000-element subsets of the set $\\{ 1, 2, 3, ... , 2015 \\}$ . From each such subset choose the least element. The arithmetic mean of all of these least elements is $\\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p + q$ .","solution":"431"} +{"question":"A square has sides of length 2. Set $S$ is the set of all line segments that have length 2 and whose endpoints are on adjacent sides of the square. The midpoints of the line segments in set $S$ enclose a region whose area to the nearest hundredth is $k.$ Find $100k.$","solution":"86"} +{"question":"A paper equilateral triangle $ABC$ has side length $12$ . The paper triangle is folded so that vertex $A$ touches a point on side $\\overline{BC}$ a distance $9$ from point $B$ . The length of the line segment along which the triangle is folded can be written as $\\frac{m\\sqrt{p}}{n}$ , where $m$ , $n$ , and $p$ are positive integers, $m$ and $n$ are relatively prime, and $p$ is not divisible by the square of any prime. Find $m+n+p$ . [asy] import cse5; size(12cm); pen tpen = defaultpen + 1.337; real a = 39\/5.0; real b = 39\/7.0; pair B = MP(\"B\", (0,0), dir(200)); pair A = MP(\"A\", (9,0), dir(-80)); pair C = MP(\"C\", (12,0), dir(-20)); pair K = (6,10.392); pair M = (a*B+(12-a)*K) \/ 12; pair N = (b*C+(12-b)*K) \/ 12; draw(B--M--N--C--cycle, tpen); draw(M--A--N--cycle); fill(M--A--N--cycle, mediumgrey); pair shift = (-20.13, 0); pair B1 = MP(\"B\", B+shift, dir(200)); pair A1 = MP(\"A\", K+shift, dir(90)); pair C1 = MP(\"C\", C+shift, dir(-20)); draw(A1--B1--C1--cycle, tpen);[\/asy]","solution":"113"} +{"question":"The complex numbers $z$ and $w$ satisfy $z^{13} = w,$ $w^{11} = z,$ and the imaginary part of $z$ is $\\sin{\\frac{m\\pi}{n}}$ , for relatively prime positive integers $m$ and $n$ with $m1$ . Find the least value of $n$ such that the sum of the zeros of $f_n$ exceeds $500,000$ .","solution":"101"} +{"question":"Let $m$ be the least positive integer divisible by $17$ whose digits sum to $17$ . Find $m$ .","solution":"476"} +{"question":"The polynomial $f(z)=az^{2018}+bz^{2017}+cz^{2016}$ has real coefficients not exceeding $2019,$ and $f\\left(\\tfrac{1+\\sqrt3i}{2}\\right)=2015+2019\\sqrt3i$ . Find the remainder when $f(1)$ is divided by $1000$ .","solution":"53"} +{"question":"Square $ABCD$ has center $O, AB=900, E$ and $F$ are on $AB$ with $AE 0$ and $a + b + c$ is an integer. The minimum possible value of $a$ can be written in the form $\\frac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p + q$ .","solution":"11"} +{"question":"The adjoining figure shows two intersecting chords in a circle, with $B$ on minor arc $AD$ . Suppose that the radius of the circle is $5$ , that $BC=6$ , and that $AD$ is bisected by $BC$ . Suppose further that $AD$ is the only chord starting at $A$ which is bisected by $BC$ . It follows that the sine of the central angle of minor arc $AB$ is a rational number. If this number is expressed as a fraction $\\frac{m}{n}$ in lowest terms, what is the product $mn$ ? [asy]size(140); defaultpen(linewidth(.8pt)+fontsize(11pt)); dotfactor=1; pair O1=(0,0); pair A=(-0.91,-0.41); pair B=(-0.99,0.13); pair C=(0.688,0.728); pair D=(-0.25,0.97); path C1=Circle(O1,1); draw(C1); label(\"$A$\",A,W); label(\"$B$\",B,W); label(\"$C$\",C,NE); label(\"$D$\",D,N); draw(A--D); draw(B--C); pair F=intersectionpoint(A--D,B--C); add(pathticks(A--F,1,0.5,0,3.5)); add(pathticks(F--D,1,0.5,0,3.5)); [\/asy]","solution":"175"} +{"question":"Let $n$ be the least positive integer for which $149^n-2^n$ is divisible by $3^3\\cdot5^5\\cdot7^7.$ Find the number of positive integer divisors of $n.$","solution":"270"} +{"question":"For each positive integer $n,$ let $f(n) = \\sum_{k = 1}^{100} \\lfloor \\log_{10} (kn) \\rfloor$ . Find the largest value of $n$ for which $f(n) \\le 300$ . Note: $\\lfloor x \\rfloor$ is the greatest integer less than or equal to $x$ .","solution":"109"} +{"question":"A circle with radius $6$ is externally tangent to a circle with radius $24$ . Find the area of the triangular region bounded by the three common tangent lines of these two circles.","solution":"192"} +{"question":"Polyhedron $ABCDEFG$ has six faces. Face $ABCD$ is a square with $AB = 12;$ face $ABFG$ is a trapezoid with $\\overline{AB}$ parallel to $\\overline{GF},$ $BF = AG = 8,$ and $GF = 6;$ and face $CDE$ has $CE = DE = 14.$ The other three faces are $ADEG, BCEF,$ and $EFG.$ The distance from $E$ to face $ABCD$ is 12. Given that $EG^2 = p - q\\sqrt {r},$ where $p, q,$ and $r$ are positive integers and $r$ is not divisible by the square of any prime, find $p + q + r.$","solution":"163"} +{"question":"A set of positive numbers has the $triangle~property$ if it has three distinct elements that are the lengths of the sides of a triangle whose area is positive. Consider sets $\\{4, 5, 6, \\ldots, n\\}$ of consecutive positive integers, all of whose ten-element subsets have the triangle property. What is the largest possible value of $n$ ?","solution":"253"} +{"question":"A semicircle with diameter $d$ is contained in a square whose sides have length 8. Given the maximum value of $d$ is $m - \\sqrt{n},$ find $m+n.$","solution":"544"} +{"question":"Find the sum of all positive integers $b < 1000$ such that the base- $b$ integer $36_{b}$ is a perfect square and the base- $b$ integer $27_{b}$ is a perfect cube.","solution":"371"} +{"question":"The numbers of apples growing on each of six apple trees form an arithmetic sequence where the greatest number of apples growing on any of the six trees is double the least number of apples growing on any of the six trees. The total number of apples growing on all six trees is $990.$ Find the greatest number of apples growing on any of the six trees.","solution":"220"} +{"question":"In triangle $ABC$ , $AC=13$ , $BC=14$ , and $AB=15$ . Points $M$ and $D$ lie on $AC$ with $AM=MC$ and $\\angle ABD = \\angle DBC$ . Points $N$ and $E$ lie on $AB$ with $AN=NB$ and $\\angle ACE = \\angle ECB$ . Let $P$ be the point, other than $A$ , of intersection of the circumcircles of $\\triangle AMN$ and $\\triangle ADE$ . Ray $AP$ meets $BC$ at $Q$ . The ratio $\\frac{BQ}{CQ}$ can be written in the form $\\frac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m-n$ .","solution":"218"} +{"question":"Let $x$ be a real number such that $\\sin^{10}x+\\cos^{10} x = \\tfrac{11}{36}$ . Then $\\sin^{12}x+\\cos^{12} x = \\tfrac{m}{n}$ where $m$ and $n$ are relatively prime positive integers. Find $m+n$ .","solution":"67"} +{"question":"A solid in the shape of a right circular cone is 4 inches tall and its base has a 3-inch radius. The entire surface of the cone, including its base, is painted. A plane parallel to the base of the cone divides the cone into two solids, a smaller cone-shaped solid $C$ and a frustum-shaped solid $F,$ in such a way that the ratio between the areas of the painted surfaces of $C$ and $F$ and the ratio between the volumes of $C$ and $F$ are both equal to $k.$ Given that $k=m\/n,$ where $m$ and $n$ are relatively prime positive integers, find $m+n.$","solution":"512"} +{"question":"Let $x,$ $y,$ and $z$ be positive real numbers satisfying the system of equations: \\begin{align*} \\sqrt{2x-xy} + \\sqrt{2y-xy} &= 1 \\\\ \\sqrt{2y-yz} + \\sqrt{2z-yz} &= \\sqrt2 \\\\ \\sqrt{2z-zx} + \\sqrt{2x-zx} &= \\sqrt3. \\end{align*} Then $\\left[ (1-x)(1-y)(1-z) \\right]^2$ can be written as $\\frac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$","solution":"33"} +{"question":"Positive integers $a$ and $b$ satisfy the condition \\[\\log_2(\\log_{2^a}(\\log_{2^b}(2^{1000}))) = 0.\\] Find the sum of all possible values of $a+b$ .","solution":"881"} +{"question":"If $\\tan x+\\tan y=25$ and $\\cot x + \\cot y=30$ , what is $\\tan(x+y)$ ?","solution":"150"} +{"question":"Squares $ABCD$ and $EFGH$ have a common center and $\\overline{AB} || \\overline{EF}$ . The area of $ABCD$ is 2016, and the area of $EFGH$ is a smaller positive integer. Square $IJKL$ is constructed so that each of its vertices lies on a side of $ABCD$ and each vertex of $EFGH$ lies on a side of $IJKL$ . Find the difference between the largest and smallest positive integer values for the area of $IJKL$ .","solution":"840"} +{"question":"Robert has 4 indistinguishable gold coins and 4 indistinguishable silver coins. Each coin has an engraving of one face on one side, but not on the other. He wants to stack the eight coins on a table into a single stack so that no two adjacent coins are face to face. Find the number of possible distinguishable arrangements of the 8 coins.","solution":"630"} +{"question":"Let $\\frac{m}{n}$ , in lowest terms, be the probability that a randomly chosen positive divisor of $10^{99}$ is an integer multiple of $10^{88}$ . Find $m + n$ .","solution":"634"} +{"question":"Positive numbers $x$ , $y$ , and $z$ satisfy $xyz = 10^{81}$ and $(\\log_{10}x)(\\log_{10} yz) + (\\log_{10}y) (\\log_{10}z) = 468$ . Find $\\sqrt {(\\log_{10}x)^2 + (\\log_{10}y)^2 + (\\log_{10}z)^2}$ .","solution":"75"} +{"question":"Find the sum of all positive integers $a=2^n3^m$ where $n$ and $m$ are non-negative integers, for which $a^6$ is not a divisor of $6^a$ .","solution":"42"} +{"question":"Let $x_1=97$ , and for $n>1$ let $x_n=\\frac{n}{x_{n-1}}$ . Calculate the product $x_1x_2 \\ldots x_8$ .","solution":"384"} +{"question":"How many positive integers $N$ less than $1000$ are there such that the equation $x^{\\lfloor x\\rfloor} = N$ has a solution for $x$ ?","solution":"412"} +{"question":"Two geometric sequences $a_1, a_2, a_3, \\ldots$ and $b_1, b_2, b_3, \\ldots$ have the same common ratio, with $a_1 = 27$ , $b_1=99$ , and $a_{15}=b_{11}$ . Find $a_9$ .","solution":"363"} +{"question":"For any positive integer $a,$ $\\sigma(a)$ denotes the sum of the positive integer divisors of $a$ . Let $n$ be the least positive integer such that $\\sigma(a^n)-1$ is divisible by $2021$ for all positive integers $a$ . Find the sum of the prime factors in the prime factorization of $n$ .","solution":"125"} +{"question":"A positive integer $N$ has base-eleven representation $\\underline{a}\\kern 0.1em\\underline{b}\\kern 0.1em\\underline{c}$ and base-eight representation $\\underline1\\kern 0.1em\\underline{b}\\kern 0.1em\\underline{c}\\kern 0.1em\\underline{a},$ where $a,b,$ and $c$ represent (not necessarily distinct) digits. Find the least such $N$ expressed in base ten.","solution":"621"} +{"question":"A point $P$ is chosen in the interior of $\\triangle ABC$ such that when lines are drawn through $P$ parallel to the sides of $\\triangle ABC$ , the resulting smaller triangles $t_{1}$ , $t_{2}$ , and $t_{3}$ in the figure, have areas $4$ , $9$ , and $49$ , respectively. Find the area of $\\triangle ABC$ . [asy] size(200); pathpen=black+linewidth(0.65);pointpen=black; pair A=(0,0),B=(12,0),C=(4,5); D(A--B--C--cycle); D(A+(B-A)*3\/4--A+(C-A)*3\/4); D(B+(C-B)*5\/6--B+(A-B)*5\/6);D(C+(B-C)*5\/12--C+(A-C)*5\/12); MP(\"A\",C,N);MP(\"B\",A,SW);MP(\"C\",B,SE); \/* sorry mixed up points according to resources diagram. *\/ MP(\"t_3\",(A+B+(B-A)*3\/4+(A-B)*5\/6)\/2+(-1,0.8),N); MP(\"t_2\",(B+C+(B-C)*5\/12+(C-B)*5\/6)\/2+(-0.3,0.1),WSW); MP(\"t_1\",(A+C+(C-A)*3\/4+(A-C)*5\/12)\/2+(0,0.15),ESE); [\/asy]","solution":"144"} +{"question":"Find the number of sets $\\{a,b,c\\}$ of three distinct positive integers with the property that the product of $a,b,$ and $c$ is equal to the product of $11,21,31,41,51,$ and $61$ .","solution":"728"} +{"question":"A straight river that is $264$ meters wide flows from west to east at a rate of $14$ meters per minute. Melanie and Sherry sit on the south bank of the river with Melanie a distance of $D$ meters downstream from Sherry. Relative to the water, Melanie swims at $80$ meters per minute, and Sherry swims at $60$ meters per minute. At the same time, Melanie and Sherry begin swimming in straight lines to a point on the north bank of the river that is equidistant from their starting positions. The two women arrive at this point simultaneously. Find $D.$","solution":"550"} +{"question":"Let $z$ be a complex number with $|z|=2014$ . Let $P$ be the polygon in the complex plane whose vertices are $z$ and every $w$ such that $\\frac{1}{z+w}=\\frac{1}{z}+\\frac{1}{w}$ . Then the area enclosed by $P$ can be written in the form $n\\sqrt{3}$ , where $n$ is an integer. Find the remainder when $n$ is divided by $1000$ .","solution":"147"} +{"question":"Ellina has twelve blocks, two each of red ( $\\textbf{R}$ ), blue ( $\\textbf{B}$ ), yellow ( $\\textbf{Y}$ ), green ( $\\textbf{G}$ ), orange ( $\\textbf{O}$ ), and purple ( $\\textbf{P}$ ). Call an arrangement of blocks $\\textit{even}$ if there is an even number of blocks between each pair of blocks of the same color. For example, the arrangement \\[\\textbf{R B B Y G G Y R O P P O}\\] is even. Ellina arranges her blocks in a row in random order. The probability that her arrangement is even is $\\frac{m}{n},$ where $m$ and $n$ are relatively prime positive integers. Find $m+n.$ ","solution":"247"} +{"question":"Consider the set of points that are inside or within one unit of a rectangular parallelepiped (box) that measures 3 by 4 by 5 units. Given that the volume of this set is $\\frac{m + n \\pi}{p},$ where $m, n,$ and $p$ are positive integers, and $n$ and $p$ are relatively prime, find $m + n + p.$","solution":"505"} +{"question":"How many positive integers have exactly three proper divisors (positive integral divisors excluding itself), each of which is less than 50?","solution":"109"} +{"question":"Let $(a,b,c)$ be a real solution of the system of equations $x^3 - xyz = 2$ , $y^3 - xyz = 6$ , $z^3 - xyz = 20$ . The greatest possible value of $a^3 + b^3 + c^3$ can be written in the form $\\frac {m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"158"} +{"question":"Let $ABCD$ be a square, and let $E$ and $F$ be points on $\\overline{AB}$ and $\\overline{BC},$ respectively. The line through $E$ parallel to $\\overline{BC}$ and the line through $F$ parallel to $\\overline{AB}$ divide $ABCD$ into two squares and two nonsquare rectangles. The sum of the areas of the two squares is $\\frac{9}{10}$ of the area of square $ABCD.$ Find $\\frac{AE}{EB} + \\frac{EB}{AE}.$","solution":"18"} +{"question":"Ten identical crates each of dimensions $3$ ft $\\times$ $4$ ft $\\times$ $6$ ft. The first crate is placed flat on the floor. Each of the remaining nine crates is placed, in turn, flat on top of the previous crate, and the orientation of each crate is chosen at random. Let $\\frac {m}{n}$ be the probability that the stack of crates is exactly $41$ ft tall, where $m$ and $n$ are relatively prime positive integers. Find $m$ .","solution":"190"} +{"question":"Call a set $S$ product-free if there do not exist $a, b, c \\in S$ (not necessarily distinct) such that $a b = c$ . For example, the empty set and the set $\\{16, 20\\}$ are product-free, whereas the sets $\\{4, 16\\}$ and $\\{2, 8, 16\\}$ are not product-free. Find the number of product-free subsets of the set $\\{1, 2, 3, 4, \\ldots, 7, 8, 9, 10\\}$ .","solution":"252"} +{"question":"In parallelogram $ABCD$ , point $M$ is on $\\overline{AB}$ so that $\\frac {AM}{AB} = \\frac {17}{1000}$ and point $N$ is on $\\overline{AD}$ so that $\\frac {AN}{AD} = \\frac {17}{2009}$ . Let $P$ be the point of intersection of $\\overline{AC}$ and $\\overline{MN}$ . Find $\\frac {AC}{AP}$ .","solution":"177"} +{"question":"Let $S$ be the set of points whose coordinates $x,$ $y,$ and $z$ are integers that satisfy $0\\le x\\le2,$ $0\\le y\\le3,$ and $0\\le z\\le4.$ Two distinct points are randomly chosen from $S.$ The probability that the midpoint of the segment they determine also belongs to $S$ is $m\/n,$ where $m$ and $n$ are relatively prime positive integers. Find $m + n.$","solution":"200"} +{"question":"Sarah intended to multiply a two-digit number and a three-digit number, but she left out the multiplication sign and simply placed the two-digit number to the left of the three-digit number, thereby forming a five-digit number. This number is exactly nine times the product Sarah should have obtained. What is the sum of the two-digit number and the three-digit number? ","solution":"126"} +{"question":"A convex quadrilateral has area $30$ and side lengths $5, 6, 9,$ and $7,$ in that order. Denote by $\\theta$ the measure of the acute angle formed by the diagonals of the quadrilateral. Then $\\tan \\theta$ can be written in the form $\\tfrac{m}{n}$ , where $m$ and $n$ are relatively prime positive integers. Find $m + n$ .","solution":"47"} +{"question":"There is a unique angle $\\theta$ between $0^\\circ$ and $90^\\circ$ such that for nonnegative integers $n,$ the value of $\\tan(2^n\\theta)$ is positive when $n$ is a multiple of $3$ , and negative otherwise. The degree measure of $\\theta$ is $\\tfrac{p}{q}$ , where $p$ and $q$ are relatively prime positive integers. Find $p+q$ .","solution":"547"} +{"question":"Given that $x, y,$ and $z$ are real numbers that satisfy: \\begin{align*} x &= \\sqrt{y^2-\\frac{1}{16}}+\\sqrt{z^2-\\frac{1}{16}}, \\\\ y &= \\sqrt{z^2-\\frac{1}{25}}+\\sqrt{x^2-\\frac{1}{25}}, \\\\ z &= \\sqrt{x^2 - \\frac 1{36}}+\\sqrt{y^2-\\frac 1{36}}, \\end{align*} and that $x+y+z = \\frac{m}{\\sqrt{n}},$ where $m$ and $n$ are positive integers and $n$ is not divisible by the square of any prime, find $m+n.$","solution":"9"} +{"question":"A deck of forty cards consists of four 1's, four 2's,..., and four 10's. A matching pair (two cards with the same number) is removed from the deck. Given that these cards are not returned to the deck, let $m\/n$ be the probability that two randomly selected cards also form a pair, where $m$ and $n$ are relatively prime positive integers. Find $m + n.$","solution":"758"} +{"question":"The complex numbers $z$ and $w$ satisfy the system \\[z + \\frac{20i}w = 5+i\\] \\[w+\\frac{12i}z = -4+10i\\] Find the smallest possible value of $\\vert zw\\vert^2$ .","solution":"40"} +{"question":"Three numbers, $a_1, a_2, a_3$ , are drawn randomly and without replacement from the set $\\{1, 2, 3,\\ldots, 1000\\}$ . Three other numbers, $b_1, b_2, b_3$ , are then drawn randomly and without replacement from the remaining set of $997$ numbers. Let $p$ be the probability that, after suitable rotation, a brick of dimensions $a_1 \\times a_2 \\times a_3$ can be enclosed in a box of dimension $b_1 \\times b_2 \\times b_3$ , with the sides of the brick parallel to the sides of the box. If $p$ is written as a fraction in lowest terms, what is the sum of the numerator and denominator?","solution":"5"} +{"question":"Segments $\\overline{AB}, \\overline{AC},$ and $\\overline{AD}$ are edges of a cube and $\\overline{AG}$ is a diagonal through the center of the cube. Point $P$ satisfies $BP=60\\sqrt{10}$ , $CP=60\\sqrt{5}$ , $DP=120\\sqrt{2}$ , and $GP=36\\sqrt{7}$ . Find $AP.$","solution":"192"} +{"question":"Define an ordered triple $(A, B, C)$ of sets to be $\\textit{minimally intersecting}$ if $|A \\cap B| = |B \\cap C| = |C \\cap A| = 1$ and $A \\cap B \\cap C = \\emptyset$ . For example, $(\\{1,2\\},\\{2,3\\},\\{1,3,4\\})$ is a minimally intersecting triple. Let $N$ be the number of minimally intersecting ordered triples of sets for which each set is a subset of $\\{1,2,3,4,5,6,7\\}$ . Find the remainder when $N$ is divided by $1000$ . Note : $|S|$ represents the number of elements in the set $S$ .","solution":"760"} +{"question":"Find the number of rational numbers $r$ , $00.$ Given that $a_1 + a_2 + a_3 + a_4 + a_5 = m\/n,$ where $m$ and $n$ are relatively prime positive integers, find $m+n.$","solution":"482"} +{"question":"A solid rectangular block is formed by gluing together $N$ congruent 1-cm cubes face to face. When the block is viewed so that three of its faces are visible, exactly 231 of the 1-cm cubes cannot be seen. Find the smallest possible value of $N.$","solution":"384"} +{"question":"On a long straight stretch of one-way single-lane highway, cars all travel at the same speed and all obey the safety rule: the distance from the back of the car ahead to the front of the car behind is exactly one car length for each 15 kilometers per hour of speed or fraction thereof (Thus the front of a car traveling 52 kilometers per hour will be four car lengths behind the back of the car in front of it.) A photoelectric eye by the side of the road counts the number of cars that pass in one hour. Assuming that each car is 4 meters long and that the cars can travel at any speed, let $M$ be the maximum whole number of cars that can pass the photoelectric eye in one hour. Find the quotient when $M$ is divided by 10.","solution":"375"} +{"question":"Find the number of positive integers $n$ less than $1000$ for which there exists a positive real number $x$ such that $n=x\\lfloor x \\rfloor$ . Note: $\\lfloor x \\rfloor$ is the greatest integer less than or equal to $x$ .","solution":"496"} +{"question":"Convex pentagon $ABCDE$ has side lengths $AB=5$ , $BC=CD=DE=6$ , and $EA=7$ . Moreover, the pentagon has an inscribed circle (a circle tangent to each side of the pentagon). Find the area of $ABCDE$ .","solution":"60"} +{"question":"Ana, Bob, and Cao bike at constant rates of $8.6$ meters per second, $6.2$ meters per second, and $5$ meters per second, respectively. They all begin biking at the same time from the northeast corner of a rectangular field whose longer side runs due west. Ana starts biking along the edge of the field, initially heading west, Bob starts biking along the edge of the field, initially heading south, and Cao bikes in a straight line across the field to a point $D$ on the south edge of the field. Cao arrives at point $D$ at the same time that Ana and Bob arrive at $D$ for the first time. The ratio of the field's length to the field's width to the distance from point $D$ to the southeast corner of the field can be represented as $p\u00a0: q\u00a0: r$ , where $p$ , $q$ , and $r$ are positive integers with $p$ and $q$ relatively prime. Find $p+q+r$ .","solution":"61"} +{"question":"Let $\\triangle ABC$ be an isosceles triangle with $\\angle A = 90^\\circ.$ There exists a point $P$ inside $\\triangle ABC$ such that $\\angle PAB = \\angle PBC = \\angle PCA$ and $AP = 10.$ Find the area of $\\triangle ABC.$","solution":"250"} +{"question":"Let $f(x)=(x^2+3x+2)^{\\cos(\\pi x)}$ . Find the sum of all positive integers $n$ for which $\\left |\\sum_{k=1}^n\\log_{10}f(k)\\right|=1.$","solution":"21"} +{"question":"Triangle $ABC$ has side lengths $AB = 9$ , $BC =$ $5\\sqrt{3}$ , and $AC = 12$ . Points $A = P_{0}, P_{1}, P_{2}, ... , P_{2450} = B$ are on segment $\\overline{AB}$ with $P_{k}$ between $P_{k-1}$ and $P_{k+1}$ for $k = 1, 2, ..., 2449$ , and points $A = Q_{0}, Q_{1}, Q_{2}, ... , Q_{2450} = C$ are on segment $\\overline{AC}$ with $Q_{k}$ between $Q_{k-1}$ and $Q_{k+1}$ for $k = 1, 2, ..., 2449$ . Furthermore, each segment $\\overline{P_{k}Q_{k}}$ , $k = 1, 2, ..., 2449$ , is parallel to $\\overline{BC}$ . The segments cut the triangle into $2450$ regions, consisting of $2449$ trapezoids and $1$ triangle. Each of the $2450$ regions has the same area. Find the number of segments $\\overline{P_{k}Q_{k}}$ , $k = 1, 2, ..., 2450$ , that have rational length.","solution":"20"} +{"question":"In quadrilateral $ABCD , \\angle B$ is a right angle, diagonal $\\overline{AC}$ is perpendicular to $\\overline{CD}, AB=18, BC=21,$ and $CD=14.$ Find the perimeter of $ABCD.$","solution":"84"} +{"question":"For each positive integer $n$ , let $f(n)$ be the sum of the digits in the base-four representation of $n$ and let $g(n)$ be the sum of the digits in the base-eight representation of $f(n)$ . For example, $f(2020) = f(133210_{\\text{4}}) = 10 = 12_{\\text{8}}$ , and $g(2020) = \\text{the digit sum of }12_{\\text{8}} = 3$ . Let $N$ be the least value of $n$ such that the base-sixteen representation of $g(n)$ cannot be expressed using only the digits $0$ through $9$ . Find the remainder when $N$ is divided by $1000$ .","solution":"151"} +{"question":"Let $\\tau(n)$ denote the number of positive integer divisors of $n$ . Find the sum of the six least positive integers $n$ that are solutions to $\\tau (n) + \\tau (n+1) = 7$ .","solution":"540"} +{"question":"Given that $\\log_{10} \\sin x + \\log_{10} \\cos x = -1$ and that $\\log_{10} (\\sin x + \\cos x) = \\frac{1}{2} (\\log_{10} n - 1),$ find $n.$","solution":"12"} +{"question":"For nonnegative integers $a$ and $b$ with $a + b \\leq 6$ , let $T(a, b) = \\binom{6}{a} \\binom{6}{b} \\binom{6}{a + b}$ . Let $S$ denote the sum of all $T(a, b)$ , where $a$ and $b$ are nonnegative integers with $a + b \\leq 6$ . Find the remainder when $S$ is divided by $1000$ .","solution":"564"} +{"question":"Let $ABCD$ and $BCFG$ be two faces of a cube with $AB=12$ . A beam of light emanates from vertex $A$ and reflects off face $BCFG$ at point $P$ , which is $7$ units from $\\overline{BG}$ and $5$ units from $\\overline{BC}$ . The beam continues to be reflected off the faces of the cube. The length of the light path from the time it leaves point $A$ until it next reaches a vertex of the cube is given by $m\\sqrt{n}$ , where $m$ and $n$ are integers and $n$ is not divisible by the square of any prime. Find $m+n$ .","solution":"230"} +{"question":"Consider the sequence $(a_k)_{k\\ge 1}$ of positive rational numbers defined by $a_1 = \\frac{2020}{2021}$ and for $k\\ge 1$ , if $a_k = \\frac{m}{n}$ for relatively prime positive integers $m$ and $n$ , then \\[a_{k+1} = \\frac{m + 18}{n+19}.\\] Determine the sum of all positive integers $j$ such that the rational number $a_j$ can be written in the form $\\frac{t}{t+1}$ for some positive integer $t$ .","solution":"59"} +{"question":"The number $r$ can be expressed as a four-place decimal $0.abcd,$ where $a, b, c,$ and $d$ represent digits, any of which could be zero. It is desired to approximate $r$ by a fraction whose numerator is 1 or 2 and whose denominator is an integer. The closest such fraction to $r$ is $\\frac 27.$ What is the number of possible values for $r$ ?","solution":"417"} +{"question":"Let $N = \\sum_{k = 1}^{1000} k ( \\lceil \\log_{\\sqrt{2}} k \\rceil - \\lfloor \\log_{\\sqrt{2}} k \\rfloor )$ Find the remainder when $N$ is divided by 1000. ( $\\lfloor{k}\\rfloor$ is the greatest integer less than or equal to $k$ , and $\\lceil{k}\\rceil$ is the least integer greater than or equal to $k$ .)","solution":"477"} +{"question":"In trapezoid $ABCD$ , leg $\\overline{BC}$ is perpendicular to bases $\\overline{AB}$ and $\\overline{CD}$ , and diagonals $\\overline{AC}$ and $\\overline{BD}$ are perpendicular. Given that $AB=\\sqrt{11}$ and $AD=\\sqrt{1001}$ , find $BC^2$ .","solution":"110"} +{"question":"Let $x=\\frac{4}{(\\sqrt{5}+1)(\\sqrt[4]{5}+1)(\\sqrt[8]{5}+1)(\\sqrt[16]{5}+1)}.$ Find $(x+1)^{48}.$","solution":"125"} +{"question":"Let $P(x) = x^2 - 3x - 9$ . A real number $x$ is chosen at random from the interval $5 \\le x \\le 15$ . The probability that $\\left\\lfloor\\sqrt{P(x)}\\right\\rfloor = \\sqrt{P(\\lfloor x \\rfloor)}$ is equal to $\\frac{\\sqrt{a} + \\sqrt{b} + \\sqrt{c} - d}{e}$ , where $a$ , $b$ , $c$ , $d$ , and $e$ are positive integers. Find $a + b + c + d + e$ .","solution":"850"}