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Sarah places four ounces of coffee into an eight-ounce cup and four ounces of cream into a second cup of the same size. She then pours half the coffee from the first cup to the second and, after stirring thoroughly, pours half the liquid in the second cup back to the first. What fraction of the liquid in the first cup ...
\frac{2}{5}
We will analyze the problem step by step to determine the fraction of the liquid in the first cup that is now cream. #### Step 1: Initial Setup - **Cup 1**: 4 ounces of coffee. - **Cup 2**: 4 ounces of cream. #### Step 2: Pouring Half the Coffee from Cup 1 to Cup 2 - Amount of coffee transferred from Cup 1 to Cup 2 =...
0.8125
3,854.8125
3,298.461538
6,265.666667
Gauss is a famous German mathematician, known as the "Prince of Mathematics". There are 110 achievements named after "Gauss". Let $x\in\mathbb{R}$, use $[x]$ to represent the largest integer not exceeding $x$, and use $\{x\}=x-[x]$ to represent the non-negative fractional part of $x$. Then, $y=[x]$ is called the Gauss ...
3024+ \sqrt {3}
0
7,726.3125
-1
7,726.3125
In $\triangle ABC$, the sides opposite to angles $A$, $B$, and $C$ are denoted as $a$, $b$, and $c$, respectively. If $(\sqrt{3}b-c)\cos A=a\cos C$, then $\cos A=$_______.
\frac{\sqrt{3}}{3}
0
4,019.9375
-1
4,019.9375
Pablo buys popsicles for his friends. The store sells single popsicles for $1 each, 3-popsicle boxes for $2, and 5-popsicle boxes for $3. What is the greatest number of popsicles that Pablo can buy with $8?
13
To determine the greatest number of popsicles Pablo can buy with $8, we need to consider the cost-effectiveness of each purchasing option: 1. **Single popsicle:** Costs $1 each, so the rate is $\frac{1}{1} = 1$ dollar per popsicle. 2. **3-popsicle box:** Costs $2, so the rate is $\frac{2}{3} \approx 0.67$ dollars per ...
0.875
5,399.375
5,000.428571
8,192
At a certain grocery store, cookies may be bought in boxes of $10$ or $21.$ What is the minimum positive number of cookies that must be bought so that the cookies may be split evenly among $13$ people? *Author: Ray Li*
52
0.5625
7,154.75
6,951.333333
7,416.285714
A bag contains only blue balls and green balls. There are $6$ blue balls. If the probability of drawing a blue ball at random from this bag is $\frac{1}{4}$, then the number of green balls in the bag is
18
1. **Identify the given information:** - Number of blue balls, $b = 6$. - Probability of drawing a blue ball, $P(\text{blue}) = \frac{1}{4}$. 2. **Set up the equation for the probability:** The probability of drawing a blue ball is given by the ratio of the number of blue balls to the total number of balls. L...
1
1,070.6875
1,070.6875
-1
The base three representation of $x$ is $12112211122211112222$. The first digit (on the left) of the base nine representation of $x$ is
5
To solve this problem, we need to convert the base three number $12112211122211112222_3$ to its base nine representation and find the first digit of that representation. #### Step 1: Convert from base 3 to base 10 The number in base 3 is $12112211122211112222_3$. We convert it to base 10 by evaluating each digit's con...
0.3125
6,801.375
3,767.4
8,180.454545
Suppose that $ABC$ is an isosceles triangle with $AB=AC$. Let $P$ be the point on side $AC$ so that $AP=2CP$. Given that $BP=1$, determine the maximum possible area of $ABC$.
\frac{9}{10}
Let $Q$ be the point on $AB$ so that $AQ=2BQ$, and let $X$ be the intersection of $BP$ and $CQ$. The key observation that, as we will show, $BX$ and $CX$ are fixed lengths, and the ratio of areas $[ABC]/[BCX]$ is constant. So, to maximize $[ABC]$, it is equivalent to maximize $[BCX]$. Using Menelaus' theorem on $ABP$, ...
0.625
6,996.8125
6,279.7
8,192
Solve the following equations using appropriate methods: $(1)\left(3x-1\right)^{2}=9$. $(2)x\left(2x-4\right)=\left(2-x\right)^{2}$.
-2
1
2,019.3125
2,019.3125
-1
Find the product of the solutions of: $|x| = 3(|x| - 2)$.
-9
1
1,462.6875
1,462.6875
-1
A certain clothing wholesale market sells a type of shirt, with a purchase price of $50$ yuan per shirt. It is stipulated that the selling price of each shirt is not lower than the purchase price. According to a market survey, the monthly sales volume $y$ (in units) and the selling price $x$ (in yuan) per unit satisfy ...
19500
0.8125
6,826.8125
6,511.769231
8,192
There exists a real number $k$ such that the equation \[\begin{pmatrix} 3 \\ 5 \end{pmatrix} + t \begin{pmatrix} 4 \\ -7 \end{pmatrix} = \begin{pmatrix} 2 \\ -2 \end{pmatrix} + s \begin{pmatrix} -1 \\ k \end{pmatrix}\]does not have any solutions in $t$ and $s$. Find $k$.
\frac{7}{4}
1
2,667.375
2,667.375
-1
For a certain positive integer $n$ less than $1000$, the decimal equivalent of $\frac{1}{n}$ is $0.\overline{abcdef}$, a repeating decimal of period of $6$, and the decimal equivalent of $\frac{1}{n+6}$ is $0.\overline{wxyz}$, a repeating decimal of period $4$. In which interval does $n$ lie?
[201,400]
1. **Understanding the repeating decimals**: Given that $\frac{1}{n} = 0.\overline{abcdef}$ has a repeating period of 6, it can be represented as $\frac{abcdef}{999999}$. This implies that $n$ divides $999999$. Similarly, $\frac{1}{n+6} = 0.\overline{wxyz}$ has a repeating period of 4, so it can be represented as $\fra...
0
8,051.375
-1
8,051.375
Given a triangle $ABC$ with sides opposite angles $A$, $B$, $C$ denoted by $a$, $b$, $c$ respectively, and with $b = 3$, $c = 2$, and the area $S_{\triangle ABC} = \frac{3\sqrt{3}}{2}$: 1. Determine the value of angle $A$; 2. When angle $A$ is obtuse, find the height from vertex $B$ to side $BC$.
\frac{3\sqrt{57}}{19}
0
7,644.0625
-1
7,644.0625
Let $X,$ $Y,$ and $Z$ be points on the line such that $\frac{XZ}{ZY} = 3$. If $Y = (2, 6)$ and $Z = (-4, 8)$, determine the sum of the coordinates of point $X$.
-8
0.4375
6,972.3125
6,695.571429
7,187.555556
Given $\tan\alpha= \frac {1}{2}$ and $\tan(\alpha-\beta)=- \frac {2}{5}$, calculate the value of $\tan(2\alpha-\beta)$.
-\frac{1}{12}
0
3,493.5625
-1
3,493.5625
Find all natural numbers \( x \) that satisfy the following conditions: the product of the digits of \( x \) is equal to \( 44x - 86868 \), and the sum of the digits is a cube of a natural number.
1989
0.0625
8,027.75
5,564
8,192
Given that there are 5 balls in a pocket, among which there are 2 black balls and 3 white balls, calculate the probability that two randomly drawn balls of the same color are both white.
\frac{3}{4}
0
3,070.1875
-1
3,070.1875
A ball is dropped from a height of $128$ meters, and each time it hits the ground, it bounces back to half of its original height. When it hits the ground for the $9$th time, the total distance it has traveled is ______ meters.
383
0.75
5,887.9375
5,119.916667
8,192
Jane is 25 years old. Dick is older than Jane. In $n$ years, where $n$ is a positive integer, Dick's age and Jane's age will both be two-digit number and will have the property that Jane's age is obtained by interchanging the digits of Dick's age. Let $d$ be Dick's present age. How many ordered pairs of positive intege...
25
0
8,192
-1
8,192
Let $f_1(x) = \frac23 - \frac3{3x+1},$ and for $n \ge 2,$ define $f_n(x) = f_1(f_{n-1}(x)).$ Find the value of $x$ that satisfies $f_{1001}(x) = x-3.$
\tfrac{5}{3}
0.8125
4,955.125
4,208.153846
8,192
Given a geometric sequence $\left\{a_{n}\right\}$ with real terms, and the sum of the first $n$ terms is $S_{n}$. If $S_{10} = 10$ and $S_{30} = 70$, then $S_{40}$ is equal to:
150
0.625
5,983.25
5,024.9
7,580.5
Determine the value of $-1 + 2 + 3 + 4 - 5 - 6 - 7 - 8 - 9 + \dots + 12100$, where the signs change after each perfect square.
1100000
0
8,079.875
-1
8,079.875
Two cards are dealt at random from two standard decks of 104 cards mixed together. What is the probability that the first card drawn is an ace and the second card drawn is also an ace?
\dfrac{7}{1339}
0.1875
6,426.4375
4,376.666667
6,899.461538
Let $\mathcal{T}$ be the set of real numbers that can be represented as repeating decimals of the form $0.\overline{ab}$ where $a$ and $b$ are distinct digits. Find the sum of the elements of $\mathcal{T}$.
45
0.625
6,555.875
5,982.3
7,511.833333
If 640 were expressed as a sum of at least three distinct powers of 2, what would be the least possible sum of the exponents of these powers?
24
0
8,192
-1
8,192
Cassie leaves Escanaba at 8:30 AM heading for Marquette on her bike. She bikes at a uniform rate of 12 miles per hour. Brian leaves Marquette at 9:00 AM heading for Escanaba on his bike. He bikes at a uniform rate of 16 miles per hour. They both bike on the same 62-mile route between Escanaba and Marquette. At what tim...
11:00
1. **Define Variables:** Let $x$ be the number of hours after Cassie leaves Escanaba when both of them meet. Cassie leaves at 8:30 AM, so if they meet $x$ hours later, the time will be $8:30$ AM + $x$ hours. 2. **Calculate Distance Traveled by Cassie:** Cassie travels at a rate of 12 miles per hour. Therefore, i...
0.4375
5,606.4375
3,468.428571
7,269.333333
A set consists of 120 distinct blocks. Each block is one of 3 materials (plastic, wood, metal), 3 sizes (small, medium, large), 4 colors (blue, green, red, yellow), and 5 shapes (circle, hexagon, square, triangle, rectangle). How many blocks in the set differ from the 'wood small blue hexagon' in exactly 2 ways?
44
0.6875
3,910
3,305.727273
5,239.4
Given the ellipse $\frac{x^{2}}{m+1}+y^{2}=1$ $(m > 0)$ with two foci $F_{1}$ and $F_{2}$, and $E$ is a common point of the line $y=x+2$ and the ellipse, calculate the eccentricity of the ellipse when the sum of distances $|EF_{1}|+|EF_{2}|$ reaches its minimum value.
\frac{\sqrt{6}}{3}
0
7,436.4375
-1
7,436.4375
Given that the coefficients $p$ and $q$ are integers and the roots $\alpha_{1}$ and $\alpha_{2}$ are irrational, a quadratic trinomial $x^{2} + px + q$ is called an irrational quadratic trinomial. Determine the minimum sum of the absolute values of the roots among all irrational quadratic trinomials.
\sqrt{5}
0
8,192
-1
8,192
A line passes through the vectors $\mathbf{a}$ and $\mathbf{b}$. For a certain value of $k$, the vector \[ k \mathbf{a} + \frac{5}{8} \mathbf{b} \] must also lie on the line. Find $k$.
\frac{3}{8}
1
1,895.25
1,895.25
-1
Heather compares the price of a new computer at two different stores. Store $A$ offers $15\%$ off the sticker price followed by a $\$90$ rebate, and store $B$ offers $25\%$ off the same sticker price with no rebate. Heather saves $\$15$ by buying the computer at store $A$ instead of store $B$. What is the sticker price...
750
#### Step-by-step Analysis: 1. **Define the Variables:** Let the sticker price of the computer be \( x \) dollars. 2. **Calculate the Final Prices:** - At store \( A \), the price after a \( 15\% \) discount is \( 0.85x \). Then, a \( \$90 \) rebate is applied, making the final price \( 0.85x - 90 \). - At ...
1
1,641.9375
1,641.9375
-1
At the beginning of my bike ride I feel good, so I can travel 20 miles per hour. Later, I get tired and travel only 12 miles per hour. If I travel a total of 122 miles in a total time of 8 hours, for how many hours did I feel good? Express your answer as a common fraction.
\frac{13}{4}
1
1,068.8125
1,068.8125
-1
The polynomial $x^8 - 1$ is factored as \[x^8 - 1 = p_1(x) p_2(x) \dotsm p_k(x),\]where each factor $p_i(x)$ is a non-constant polynomial with real coefficients. Find the largest possible value of $k.$
5
0
8,192
-1
8,192
There exists a positive number $m$ such that the positive roots of the equation $\sqrt{3} \sin x - \cos x = m$ form an arithmetic sequence in ascending order. If the point $A(1, m)$ lies on the line $ax + by - 2 = 0 (a > 0, b > 0)$, find the minimum value of $\frac{1}{a} + \frac{2}{b}$.
\frac{9}{2}
0.25
7,823.3125
6,717.25
8,192
Let $r=H_{1}$ be the answer to this problem. Given that $r$ is a nonzero real number, what is the value of $r^{4}+4 r^{3}+6 r^{2}+4 r ?$
-1
Since $H_{1}$ is the answer, we know $r^{4}+4 r^{3}+6 r^{2}+4 r=r \Rightarrow(r+1)^{4}=r+1$. Either $r+1=0$, or $(r+1)^{3}=1 \Rightarrow r=0$. Since $r$ is nonzero, $r=-1$.
0.1875
3,428.625
3,519.333333
3,407.692308
A dodecahedron consists of two pentagonal-based pyramids glued together along their pentagonal bases, forming a polyhedron with 12 faces. Consider an ant at the top vertex of one of the pyramids, selecting randomly one of the five adjacent vertices, designated as vertex A. From vertex A, the ant then randomly selects o...
\frac{1}{5}
0.3125
7,669.6875
6,846.2
8,044
Through a simulation experiment, 20 groups of random numbers were generated: 830, 3013, 7055, 7430, 7740, 4422, 7884, 2604, 3346, 0952, 6807, 9706, 5774, 5725, 6576, 5929, 9768, 6071, 9138, 6754. If exactly three numbers are among 1, 2, 3, 4, 5, 6, it indicates that the target was hit exactly three times. Then, the pro...
25\%
0
7,270.125
-1
7,270.125
In triangle \(ABC\), angle \(A\) is \(60^\circ\) and \(AB:AC = 3:2\). Points \(M\) and \(N\) are located on sides \(AB\) and \(AC\) respectively, such that \(BM = MN = NC\). Find the ratio of the area of triangle \(AMN\) to the area of triangle \(ABC\).
4/25
0.625
6,757.5625
5,896.9
8,192
Call a set of integers "spacy" if it contains no more than one out of any three consecutive integers. How many subsets of $\{1, 2, 3, \dots, 12\}$, including the empty set, are spacy?
129
0.125
7,860.875
8,192
7,813.571429
Calculate the volume of the solid of revolution obtained by rotating a right triangle with sides 3, 4, and 5 around one of its legs that form the right angle.
12 \pi
0
6,890.8125
-1
6,890.8125
In $\triangle ABC$, the sides opposite to angles $A$, $B$, and $C$ are $a$, $b$, and $c$ respectively. Given vectors $\overrightarrow{m}=(\sin B+\sin C,\sin A+\sin B)$, $\overrightarrow{n}=(\sin B-\sin C,\sin A)$, and $\overrightarrow{m}\perp \overrightarrow{n}$. (1) Find the measure of angle $C$; (2) If $\triangle A...
2+\sqrt{3}
0.875
4,207.3125
3,877.071429
6,519
Into each row of a \( 9 \times 9 \) grid, Nigel writes the digits \( 1, 2, 3, 4, 5, 6, 7, 8, 9 \) in order, starting at one of the digits and returning to 1 after 9: for example, one row might contain \( 7, 8, 9, 1, 2, 3, 4, 5, 6 \). The grid is gorgeous if each nine-digit number read along a row or column or along the...
9^8
0
7,866.5625
-1
7,866.5625
Point $D$ lies on side $AC$ of equilateral triangle $ABC$ such that the measure of angle $DBC$ is 30 degrees. What is the ratio of the area of triangle $ADB$ to the area of triangle $CDB$?
\frac{1}{3}
0
7,063
-1
7,063
Let $n$ be the largest real solution to the equation \[\dfrac{4}{x-2} + \dfrac{6}{x-6} + \dfrac{13}{x-13} + \dfrac{15}{x-15} = x^2 - 7x - 6\] There are positive integers $p, q,$ and $r$ such that $n = p + \sqrt{q + \sqrt{r}}$. Find $p+q+r$.
103
0
8,192
-1
8,192
How many ordered pairs $(S, T)$ of subsets of $\{1,2,3,4,5,6,7,8,9,10\}$ are there whose union contains exactly three elements?
3240
Let the three elements in the union be $a, b$, and $c$. We know that $a$ can be only in $S$, only in $T$, or both, so there are 3 possibilities for placing it. (Recall that $S=\{a\}, T=\{b, c\}$ is different from $S=\{b, c\}, T=\{a\}$ because $S$ and $T$ are an ordered pair.) Likewise for $b$ and $c$. The other 7 eleme...
0.5
6,909.625
5,755.375
8,063.875
The cookies in a cookie jar contain a total of 100 raisins. All but one of the cookies are the same size and contain the same number of raisins. One cookie is larger and contains one more raisin than each of the others. The number of cookies in the jar is between 5 and 10, inclusive. How many raisins are in the larger ...
12
Let $n$ be the number of cookies in the cookie jar. Let $r$ be the number of raisins in each of the $n-1$ smaller, identical cookies. This means that there are $r+1$ raisins in the larger cookie. If we removed one raisin from the larger cookie, it too would have $r$ raisins and so each of the $n$ cookies would have the...
1
1,677.1875
1,677.1875
-1
Four students from Harvard, one of them named Jack, and five students from MIT, one of them named Jill, are going to see a Boston Celtics game. However, they found out that only 5 tickets remain, so 4 of them must go back. Suppose that at least one student from each school must go see the game, and at least one of Jack...
104
0.375
7,016.875
5,851.833333
7,715.9
Find $n$ such that $2^8 \cdot 3^4 \cdot 5^1 \cdot n = 10!$.
35
1
3,829.3125
3,829.3125
-1
How many three-digit numbers are divisible by 13?
69
1. **Identify the range of three-digit numbers**: Three-digit numbers range from 100 to 999. 2. **Determine the smallest and largest values of $k$ such that $13k$ is a three-digit number**: - For the smallest three-digit number, we need $13k \geq 100$. Solving for $k$, we get: \[ k \geq \frac{100}{13} \ap...
1
2,510
2,510
-1
Given triangle \( ABC \). On the side \( AC \), which is the largest in the triangle, points \( M \) and \( N \) are marked such that \( AM = AB \) and \( CN = CB \). It turns out that angle \( NBM \) is three times smaller than angle \( ABC \). Find \( \angle ABC \).
108
0
8,173.25
-1
8,173.25
Regions I, II and III are bounded by squares. The perimeter of region I is 12 units and the perimeter of region II is 24 units. What is the ratio of the area of region I to the area of region III? Express your answer as a common fraction. [asy] draw((0,0)--(9,0)--(9,9)--(0,9)--(0,0)--cycle,linewidth(2)); draw((9,0)--(...
\frac{1}{9}
0.4375
6,948.8125
5,557.142857
8,031.222222
A triangle can be formed having side lengths 4, 5, and 8. It is impossible, however, to construct a triangle with side lengths 4, 5, and 9. Ron has eight sticks, each having an integer length. He observes that he cannot form a triangle using any three of these sticks as side lengths. The shortest possible length of the...
21
0.125
8,082.0625
7,312.5
8,192
A function $f:\{1,2,3,4,5\} \rightarrow\{1,2,3,4,5\}$ is said to be nasty if there do not exist distinct $a, b \in\{1,2,3,4,5\}$ satisfying $f(a)=b$ and $f(b)=a$. How many nasty functions are there?
1950
We use complementary counting. There are $5^{5}=3125$ total functions. If there is at least one pair of numbers which map to each other, there are \binom{5}{2}=10$ ways to choose the pair and $5^{3}=125$ ways to assign the other values of the function for a total of 1250 . But we overcount each time there are two such ...
0
8,179.1875
-1
8,179.1875
Find all positive integers $n$ such that there are $k \geq 2$ positive rational numbers $a_1, a_2, \ldots, a_k$ satisfying $a_1 + a_2 + \ldots + a_k = a_1 \cdot a_2 \cdots a_k = n.$
4 \text{ or } n \geq 6
We are tasked with finding all positive integers \( n \) for which there exist \( k \geq 2 \) positive rational numbers \( a_1, a_2, \ldots, a_k \) satisfying the conditions: \[ a_1 + a_2 + \cdots + a_k = a_1 \cdot a_2 \cdots a_k = n. \] To find the possible values of \( n \), we analyze the problem for small values...
0
8,192
-1
8,192
If $\frac{1}{6} + \frac{1}{3} = \frac{1}{x}$, what is the value of $x$?
2
Simplifying, $\frac{1}{6} + \frac{1}{3} = \frac{1}{6} + \frac{2}{6} = \frac{3}{6} = \frac{1}{2}$. Thus, $\frac{1}{x} = \frac{1}{2}$ and so $x = 2$.
0.9375
1,565.8125
1,124.066667
8,192
What is $6 \div 0.\overline{6}$?
9
1
1,980.25
1,980.25
-1
Find the smallest positive integer $n$ such that for any $n$ mutually coprime integers greater than 1 and not exceeding 2009, there is at least one prime number among them.
15
0.0625
8,035.9375
5,695
8,192
In the Cartesian coordinate plane $(xOy)$, a point $A(2,0)$, a moving point $B$ on the curve $y= \sqrt {1-x^{2}}$, and a point $C$ in the first quadrant form an isosceles right triangle $ABC$ with $\angle A=90^{\circ}$. The maximum length of the line segment $OC$ is _______.
1+2 \sqrt {2}
0
6,788.1875
-1
6,788.1875
Find the distance from the point \( M_{0} \) to the plane passing through the three points \( M_{1}, M_{2}, M_{3} \). \( M_{1}(1, 3, 0) \) \( M_{2}(4, -1, 2) \) \( M_{3}(3, 0, 1) \) \( M_{0}(4, 3, 0) \)
\sqrt{6}
0.875
3,795.8125
3,578.214286
5,319
Three $\text{A's}$, three $\text{B's}$, and three $\text{C's}$ are placed in the nine spaces so that each row and column contains one of each letter. If $\text{A}$ is placed in the upper left corner, how many arrangements are possible?
4
1. **Fixing A in the upper left corner**: We start by placing an A in the upper left corner of the grid. The grid now looks like this: \[ \begin{array}{|c|c|c|} \hline A & & \\ \hline & & \\ \hline & & \\ \hline \end{array} \] 2. **Placing the remaining A's**: Since eac...
0.1875
7,965.625
6,984.666667
8,192
Simplify: $\frac{2^{n+4} - 2(2^n)}{2(2^{n+3})}$. Express your answer as a common fraction.
\frac{7}{8}
1
1,812.75
1,812.75
-1
Rose fills each of the rectangular regions of her rectangular flower bed with a different type of flower. The lengths, in feet, of the rectangular regions in her flower bed are as shown in the figure. She plants one flower per square foot in each region. Asters cost $\$1$ each, begonias $\$1.50$ each, cannas $\$2$ each...
108
0
7,871
-1
7,871
Given that the odometer initially showed 35,400 miles and the driver filled the gas tank with 8 gallons of gasoline, and later filled the tank again with 15 gallons when the odometer showed 35,680 miles, and finally filled the tank with 18 gallons of gasoline when the odometer read 36,000 miles, calculate the car's ave...
14.6
0
1,375.9375
-1
1,375.9375
A cylindrical water tank is $\frac{1}{5}$ full. If three liters were added, the tank would be $\frac{1}{4}$ full. How many liters does the tank hold when it is full?
60
1
1,283.375
1,283.375
-1
There are \(n\) girls \(G_{1}, \ldots, G_{n}\) and \(n\) boys \(B_{1}, \ldots, B_{n}\). A pair \((G_{i}, B_{j})\) is called suitable if and only if girl \(G_{i}\) is willing to marry boy \(B_{j}\). Given that there is exactly one way to pair each girl with a distinct boy that she is willing to marry, what is the maxima...
\frac{n(n+1)}{2}
We represent the problem as a graph with vertices \(G_{1}, \ldots, G_{n}, B_{1}, \ldots, B_{n}\) such that there is an edge between vertices \(G_{i}\) and \(B_{j}\) if and only if \((G_{i}, B_{j})\) is suitable, so we want to maximize the number of edges while having a unique matching. We claim the answer is \(\frac{n(...
0
7,794.1875
-1
7,794.1875
If \( a \) and \( b \) are given real numbers, and \( 1 < a < b \), then the absolute value of the difference between the average and the median of the four numbers \( 1, a+1, 2a+b, a+b+1 \) is ______.
\frac{1}{4}
0.75
5,709.0625
4,881.416667
8,192
What is the area enclosed by the graph of $|x| + |2y|$ = 10 shown here? [asy] draw((0,-10)--(0,10),Arrows); draw((-15,0)--(15,0),Arrows); label("$y$",(0,10),NE); label("$x$",(15,0),SE); draw((10,0)--(0,5)--(-10,0)--(0,-5)--cycle); [/asy]
100
1
3,153.9375
3,153.9375
-1
The fraction of the area of rectangle P Q R S that is shaded must be calculated.
\frac{1}{2}
0.5
6,599.8125
5,273.75
7,925.875
Bob Barker went back to school for a PhD in math, and decided to raise the intellectual level of The Price is Right by having contestants guess how many objects exist of a certain type, without going over. The number of points you will get is the percentage of the correct answer, divided by 10, with no points for going...
292864
$15!/\left(3^{4} \cdot 5^{3} \cdot 7^{2} \cdot 9\right)=292864$. These are Standard Young Tableaux.
0
8,022.125
-1
8,022.125
The polynomial $x^3 - 2004 x^2 + mx + n$ has integer coefficients and three distinct positive zeros. Exactly one of these is an integer, and it is the sum of the other two. How many values of $n$ are possible?
250500
0.125
8,043.875
7,419
8,133.142857
In the sequence $\{a_n\}$, two adjacent terms $a_n$ and $a_{n+1}$ are the roots of the equation $x^2 + 3nx + b_n = 0$. Given that $a_{10} = -17$, calculate the value of $b_{51}$.
5840
0.6875
5,353.375
4,466.727273
7,304
In a small town, there are $n \times n$ houses indexed by $(i, j)$ for $1 \leq i, j \leq n$ with $(1,1)$ being the house at the top left corner, where $i$ and $j$ are the row and column indices, respectively. At time 0, a fire breaks out at the house indexed by $(1, c)$, where $c \leq \frac{n}{2}$. During each subseque...
n^{2}+c^{2}-nc-c
At most $n^{2}+c^{2}-n c-c$ houses can be saved. This can be achieved under the following order of defending: $$(2, c),(2, c+1) ;(3, c-1),(3, c+2) ;(4, c-2),(4, c+3) ; \ldots \tag{6} (c+1,1),(c+1,2 c) ;(c+1,2 c+1), \ldots,(c+1, n)$$ Under this strategy, there are 2 columns (column numbers $c, c+1$ ) at which $n-1$ hous...
0
8,192
-1
8,192
A belt is installed on two pulleys with radii of 14 inches and 4 inches respectively. The belt is taut and does not intersect itself. If the distance between the points where the belt touches the two pulleys is 24 inches, find the distance between the centers of the two pulleys.
26
1
2,212.9375
2,212.9375
-1
Given $f(x)= \frac{1}{2^{x}+ \sqrt {2}}$, use the method for deriving the sum of the first $n$ terms of an arithmetic sequence to find the value of $f(-5)+f(-4)+…+f(0)+…+f(5)+f(6)$.
3 \sqrt {2}
0
7,993.9375
-1
7,993.9375
If $\|\mathbf{v}\| = 4,$ then find $\mathbf{v} \cdot \mathbf{v}.$
16
1
1,425.9375
1,425.9375
-1
Find a real number $t$ such that for any set of 120 points $P_1, \ldots P_{120}$ on the boundary of a unit square, there exists a point $Q$ on this boundary with $|P_1Q| + |P_2Q| + \cdots + |P_{120}Q| = t$.
30(1 + \sqrt{5})
We need to find a real number \( t \) such that for any set of 120 points \( P_1, \ldots, P_{120} \) on the boundary of a unit square, there exists a point \( Q \) on this boundary with \( |P_1Q| + |P_2Q| + \cdots + |P_{120}Q| = t \). Define \(\mathcal{U}\) to be a set of points \( P_1, \ldots, P_{120} \) on the boun...
0
8,187.4375
-1
8,187.4375
Let $S$ be a randomly selected four-element subset of $\{1, 2, 3, 4, 5, 6, 7, 8\}$ . Let $m$ and $n$ be relatively prime positive integers so that the expected value of the maximum element in $S$ is $\dfrac{m}{n}$ . Find $m + n$ .
41
0.5625
5,808.25
3,954.222222
8,192
Given \( \alpha, \beta \in (0, \pi) \), and \( \tan \alpha, \tan \beta \) are the roots of the equation \( x^{2} + 3x + 1 = 0 \), find the value of \( \cos(\alpha - \beta) \).
\frac{2}{3}
0.6875
6,041.5
5,064
8,192
In the Cartesian coordinate system $xOy$, the sum of distances from point $P$ to the two points $\left(0, -\sqrt{3}\right)$ and $\left(0, \sqrt{3}\right)$ is $4$. Let the trajectory of point $P$ be $C$. (Ⅰ) Find the equation of curve $C$; (Ⅱ) Find the coordinates of the vertices, the lengths of the major and minor ax...
\dfrac{\sqrt{3}}{2}
0
2,362.3125
-1
2,362.3125
Let $n \ge 3$ be an integer. What is the largest possible number of interior angles greater than $180^\circ$ in an $n$-gon in the plane, given that the $n$-gon does not intersect itself and all its sides have the same length?
0
Let \( n \ge 3 \) be an integer, and consider an \( n \)-gon in the plane with equal side lengths. We are asked to find the largest possible number of interior angles greater than \( 180^\circ \), given that the \( n \)-gon does not intersect itself. To solve this, we will use the following geometric principles: 1. ...
0
7,420.5625
-1
7,420.5625
Find the sum of all four-digit numbers, in which only the digits $1, 2, 3, 4, 5$ are used, and each digit occurs no more than once.
399960
0.75
5,233.5625
4,247.416667
8,192
The product of positive integers $x$, $y$ and $z$ equals 2004. What is the minimum possible value of the sum $x + y + z$?
174
0.5
6,982.4375
5,772.875
8,192
Let positive integers $a$, $b$, $c$, and $d$ be randomly and independently selected with replacement from the set $\{1, 2, 3,\dots, 2000\}$. Find the probability that the expression $ab+bc+cd+d+1$ is divisible by $4$.
\frac{1}{4}
0
8,022.0625
-1
8,022.0625
A function $f$ from the integers to the integers is defined as follows: \[f(n) = \left\{ \begin{array}{cl} n + 3 & \text{if $n$ is odd}, \\ n/2 & \text{if $n$ is even}. \end{array} \right.\]Suppose $k$ is odd and $f(f(f(k))) = 27.$ Find $k.$
105
1
4,406.1875
4,406.1875
-1
Evaluate $\lfloor-2.54\rfloor+\lceil25.4\rceil$.
23
1
1,570.25
1,570.25
-1
(1) Solve the inequality $\log_{\frac{1}{2}}(x+2) > -3$ (2) Calculate: $(\frac{1}{8})^{\frac{1}{3}} \times (-\frac{7}{6})^{0} + 8^{0.25} \times \sqrt[4]{2} + (\sqrt[3]{2} \times \sqrt{3})^{6}$.
\frac{221}{2}
0.25
5,512.8125
4,532.25
5,839.666667
Given the function $f(x)=\ln x+ax (a\in R)$. (1) When $a=- \frac{1}{3}$, find the extreme values of the function $f(x)$ in the interval $[e,e^{2}]$; (2) When $a=1$, the function $g(x)=f(x)- \frac{2}{t}x^{2}$ has only one zero point. Find the value of the positive number $t$.
t=2
0.75
5,263.5
4,287.333333
8,192
Find the matrix that corresponds to a dilation centered at the origin with scale factor $-3.$
\begin{pmatrix} -3 & 0 \\ 0 & -3 \end{pmatrix}
0.875
1,660.875
1,631.142857
1,869
At the refreshment point, four athletes drank all the stock of Coke-Loco lemonade. If only athlete Bystrov had drunk half as much, one-tenth of the lemonade would have been left. If, additionally, athlete Shustrov had also drunk half as much, one-eighth of the lemonade would have been left. If, additionally to both of ...
\frac{1}{6}
0.0625
7,918.625
4,599
8,139.933333
Given a polynomial $f(x) = 2x^7 + x^6 + x^4 + x^2 + 1$, calculate the value of $V_2$ using the Horner's method when $x=2$.
10
0.875
4,819.9375
4,410.5
7,686
An isosceles trapezoid is circumscribed around a circle. The longer base of the trapezoid is $16$, and one of the base angles is $\arcsin(.8)$. Find the area of the trapezoid. $\textbf{(A)}\ 72\qquad \textbf{(B)}\ 75\qquad \textbf{(C)}\ 80\qquad \textbf{(D)}\ 90\qquad \textbf{(E)}\ \text{not uniquely determined}$
80
0
3,706.875
-1
3,706.875
It takes 42 seconds for a clock to strike 7 times. How many seconds does it take for it to strike 10 times?
60
0
691.375
-1
691.375
Let $f(x)$ be a function defined for all positive real numbers satisfying the conditions $f(x) > 0$ for all $x > 0$ and \[f(x - y) = \sqrt{f(xy) + 2}\]for all $x > y > 0.$ Determine $f(2009).$
2
0.9375
4,547.4375
4,304.466667
8,192
Define an ordered quadruple of integers $(a, b, c, d)$ as interesting if $1 \le a<b<c<d \le 10$, and $a+d>b+c$. How many interesting ordered quadruples are there?
80
0
8,192
-1
8,192
Xiaoting's average score for five math tests is 85, the median is 86, and the mode is 88. What is the sum of the scores of the two lowest tests?
163
0.8125
734.8125
751.923077
660.666667
The points $(1, 3)$ and $(5, -1)$ are adjacent vertices of a square. What is the area of the square?
32
0.9375
4,115.625
3,843.866667
8,192
Find and describe the pattern by which the sequence of numbers is formed. Determine the next number in this sequence. $$ 112, 224, 448, 8816, 6612 $$
224
0
7,939.625
-1
7,939.625
In a triangle with integer side lengths, one side is four times as long as a second side, and the length of the third side is 16. What is the greatest possible perimeter of the triangle?
41
0.625
5,581.4375
4,015.1
8,192
Find all functions $ f : \mathbb{R} \rightarrow \mathbb{R} $ such that \[ f( xf(x) + 2y) = f(x^2)+f(y)+x+y-1 \] holds for all $ x, y \in \mathbb{R}$.
f(x) = x + 1
To solve the functional equation \[ f(xf(x) + 2y) = f(x^2) + f(y) + x + y - 1 \] for all real numbers \( x \) and \( y \), we need to find all possible functions \( f : \mathbb{R} \rightarrow \mathbb{R} \) that satisfy this condition. **Step 1: Initial Evaluation** Let's substitute \( y = 0 \) into the equation: ...
0
7,644.4375
-1
7,644.4375