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Given a general triangle \(ABC\) with points \(K, L, M, N, U\) on its sides: - Point \(K\) is the midpoint of side \(AC\). - Point \(U\) is the midpoint of side \(BC\). - Points \(L\) and \(M\) lie on segments \(CK\) and \(CU\) respectively, such that \(LM \parallel KU\). - Point \(N\) lies on segment \(AB\) such that...
\frac{1}{2}
0
8,192
-1
8,192
Let $I, T, E, S$ be distinct positive integers such that the product $ITEST = 2006$ . What is the largest possible value of the sum $I + T + E + S + T + 2006$ ?
2086
0.4375
7,013.3125
5,865.857143
7,905.777778
Oleg drew an empty $50 \times 50$ table and wrote a number above each column and to the left of each row. It turned out that all 100 written numbers are different, with 50 of them being rational and the remaining 50 irrational. Then, in each cell of the table, he wrote the sum of the numbers written next to its row and...
1250
0.3125
7,334.1875
6,098.4
7,895.909091
The sum of the absolute values of the terms of a finite arithmetic progression is equal to 100. If all its terms are increased by 1 or all its terms are increased by 2, in both cases the sum of the absolute values of the terms of the resulting progression will also be equal to 100. What values can the quantity \( n^{2}...
400
0.0625
8,192
8,192
8,192
A point $P$ is randomly placed in the interior of the right triangle below. What is the probability that the area of triangle $PBC$ is less than half of the area of triangle $ABC$? Express your answer as a common fraction. [asy] size(7cm); defaultpen(linewidth(0.7)); pair A=(0,5), B=(8,0), C=(0,0), P=(1.5,1.7); draw(...
\frac{3}{4}
0.5625
7,420.5625
6,927.666667
8,054.285714
Given a right circular cone with three mutually perpendicular side edges, each with a length of $\sqrt{3}$, determine the surface area of the circumscribed sphere.
9\pi
0.1875
7,859.1875
6,417
8,192
In the diagram below, $\overline{AB}\parallel \overline{CD}$ and $\angle AXE$ is $108^\circ$ less than 3 times $\angle CYX$. Find $\angle BXY$. [asy] unitsize(1inch); pair A,B,C,D,X,Y,EE,F; A = (0,0); B=(1,0); C = (0,0.8); D=(1,0.8); EE = (0.35,-0.3); F = (0.8,1.1); draw(EE--F); draw(A--B); draw(C--D); do...
54^\circ
0.1875
4,760.5625
6,542.666667
4,349.307692
$\frac{x^{2}}{9} + \frac{y^{2}}{7} = 1$, where $F_{1}$ and $F_{2}$ are the foci of the ellipse. Given that point $A$ lies on the ellipse and $\angle AF_{1}F_{2} = 45^{\circ}$, find the area of triangle $AF_{1}F_{2}$.
\frac{7}{2}
0.25
7,781.5625
6,550.25
8,192
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.
542
0.8125
5,386.375
4,738.923077
8,192
Nathaniel and Obediah play a game in which they take turns rolling a fair six-sided die and keep a running tally of the sum of the results of all rolls made. A player wins if, after he rolls, the number on the running tally is a multiple of 7. Play continues until either player wins, or else indefinitely. If Nathaniel ...
5/11
0
8,192
-1
8,192
What is $(a^3+b^3)\div(a^2-ab+b^2)$ when $a=5$ and $b=4$?
9
1
1,490.125
1,490.125
-1
In a triangle, the lengths of the three sides are integers \( l, m, n \), with \( l > m > n \). It is known that \( \left\{ \frac{3^{l}}{10^{4}} \right\} = \left\{ \frac{3^{m}}{10^{4}} \right\} = \left\{ \frac{3^{n}}{10^{4}} \right\} \), where \( \{x\} \) denotes the fractional part of \( x \) and \( [x] \) denotes the...
3003
0.3125
7,988.625
7,541.2
8,192
Square $ABCD$ has side length $30$. Point $P$ lies inside the square so that $AP = 12$ and $BP = 26$. The centroids of $\triangle{ABP}$, $\triangle{BCP}$, $\triangle{CDP}$, and $\triangle{DAP}$ are the vertices of a convex quadrilateral. What is the area of that quadrilateral? [asy] unitsize(120); pair B = (0, 0), A = ...
200
0
7,891.375
-1
7,891.375
In the Cartesian coordinate plane $(xOy)$, two acute angles $\alpha$ and $\beta$ are formed with the non-negative semi-axis of $Ox$ as the initial side. Their terminal sides intersect the unit circle at points $A$ and $B$ respectively. The vertical coordinates of $A$ and $B$ are $\frac{\sqrt{5}}{5}$ and $\frac{3\sqrt{1...
\frac{3\sqrt{10}}{10}
0
4,788.9375
-1
4,788.9375
A regular dodecagon \( Q_1 Q_2 \dotsb Q_{12} \) is drawn in the coordinate plane with \( Q_1 \) at \( (4,0) \) and \( Q_7 \) at \( (2,0) \). If \( Q_n \) is the point \( (x_n,y_n) \), compute the numerical value of the product \[ (x_1 + y_1 i)(x_2 + y_2 i)(x_3 + y_3 i) \dotsm (x_{12} + y_{12} i). \]
531440
0.5625
6,554.1875
5,280.333333
8,192
Draw a rectangle. Connect the midpoints of the opposite sides to get 4 congruent rectangles. Connect the midpoints of the lower right rectangle for a total of 7 rectangles. Repeat this process infinitely. Let $n$ be the minimum number of colors we can assign to the rectangles so that no two rectangles sharing an edge h...
(3,4)
$(3,4) \text {. }$
0
8,012.6875
-1
8,012.6875
In the land of Draconia, there are red, green, and blue dragons. Each dragon has three heads, and each head always tells the truth or always lies. Additionally, each dragon has at least one head that tells the truth. One day, 530 dragons sat around a round table, and each of them said: - 1st head: "To my left is a gre...
176
0
8,192
-1
8,192
A $5 \times 5$ square grid has the number -3 written in the upper-left square and the number 3 written in the lower-right square. In how many ways can the remaining squares be filled in with integers so that any two adjacent numbers differ by 1, where two squares are adjacent if they share a common edge (but not if the...
250
250 If the square in row $i$, column $j$ contains the number $k$, let its 'index' be $i+j-k$. The constraint on adjacent squares now says that if a square has index $r$, the squares to its right and below it each have index $r$ or $r+2$. The upper-left square has index 5, and the lower-right square has index 7, so ever...
0
7,940.625
-1
7,940.625
$\_$\_$\_$:20=24÷$\_$\_$\_$=80%=$\_$\_$\_$(fill in the blank with a fraction)=$\_$\_$\_$(fill in the blank with a decimal)
0.8
0.25
607.75
572.5
619.5
Find the complex number $z$ such that \[|z - 1| = |z + 3| = |z - i|.\]
-1 - i
1
3,268.9375
3,268.9375
-1
Given that $θ∈[0,π]$, find the probability that $\sin (θ+ \frac {π}{3}) < \frac {1}{2}$.
\frac{1}{2}
0.6875
6,350.25
5,798.818182
7,563.4
Given that Jeff, Maria, and Lee paid $90, $150, and $210 respectively, find j - m where Jeff gave Lee $j dollars and Maria gave Lee $m dollars to settle the debts such that everyone paid equally.
60
0.625
5,590.125
4,110.8
8,055.666667
The segments of two lines, enclosed between two parallel planes, are in the ratio of \( 5:9 \), and the acute angles between these lines and one of the planes are in the ratio of \( 2:1 \), respectively. Find the cosine of the smaller angle.
0.9
0
6,449.4375
-1
6,449.4375
Points $M$ , $N$ , $P$ are selected on sides $\overline{AB}$ , $\overline{AC}$ , $\overline{BC}$ , respectively, of triangle $ABC$ . Find the area of triangle $MNP$ given that $AM=MB=BP=15$ and $AN=NC=CP=25$ . *Proposed by Evan Chen*
150
0.5625
5,411.1875
4,449.777778
6,647.285714
Compute $\arcsin (-1).$ Express your answer in radians.
-\frac{\pi}{2}
1
1,131.625
1,131.625
-1
How many real numbers $x^{}_{}$ satisfy the equation $\frac{1}{5}\log_2 x = \sin (5\pi x)$?
159
Notice that the equation is satisfied twice for every sine period (which is $\frac{2}{5}$), except in the sole case when the two equations equate to $0$. In that case, the equation is satisfied twice but only at the one instance when $y=0$. Hence, it is double-counted in our final solution, so we have to subtract it ou...
0
8,192
-1
8,192
Suppose $a$ and $b$ be positive integers not exceeding 100 such that $$a b=\left(\frac{\operatorname{lcm}(a, b)}{\operatorname{gcd}(a, b)}\right)^{2}$$ Compute the largest possible value of $a+b$.
78
For any prime $p$ and a positive integer $n$, let $\nu_{p}(n)$ be the largest nonnegative integer $k$ for which $p^{k}$ divides $n$. Taking $\nu_{p}$ on both sides of the given equation, we get $$\nu_{p}(a)+\nu_{p}(b)=2 \cdot\left|\nu_{p}(a)-\nu_{p}(b)\right|$$ which means $\frac{\nu_{p}(a)}{\nu_{p}(b)} \in\left\{3, \f...
0
8,192
-1
8,192
Given the function $f(x)$ ($x \in \mathbb{R}$) that satisfies $f(x+\pi)=f(x)+\sin x$, and $f(x)=0$ when $0 \leqslant x < \pi$, determine the value of $f(\frac{23\pi}{6})$.
\frac{1}{2}
0.4375
7,441
6,475.428571
8,192
Given the sequence $\\_a{n}\_$, where $\_a{n}>0$, $\_a{1}=1$, and $\_a{n+2}=\frac{1}{a{n}+1}$, and it is known that $\_a{6}=a{2}$, find the value of $\_a{2016}+a{3}=\_\_\_\_\_\_$.
\frac{\sqrt{5}}{2}
0
5,922.3125
-1
5,922.3125
In $\triangle ABC$, the sides opposite to angles $A$, $B$, $C$ are $a$, $b$, $c$ respectively, and $b=2$. (1) If angles $A$, $B$, $C$ form an arithmetic progression, find the radius of the circumcircle of $\triangle ABC$. (2) If sides $a$, $b$, $c$ form an arithmetic progression, find the maximum area of $\triangle AB...
\sqrt{3}
0.875
5,495.625
5,110.428571
8,192
Laura and her grandmother Ana just discovered that last year, their ages were divisible by 8 and that next year, their ages will be divisible by 7. Grandma Ana is not yet 100 years old. What is Laura's age?
41
0.25
7,308.3125
6,601.5
7,543.916667
We measured the elevation angles of a tower standing on a horizontal plane from points $50 \mathrm{~m}$ and $100 \mathrm{~m}$ away from the base of the tower. The sum of the measured angles is $45^{\circ}$. How tall is the tower?
28.08
0
5,428.4375
-1
5,428.4375
Regular decagon \( ABCDEFGHIJ \) has its center at \( K \). Each of the vertices and the center are to be associated with one of the digits \( 1 \) through \( 10 \), with each digit used exactly once, in such a way that the sums of the numbers on the lines \( AKF \), \( BKG \), \( CKH \), \( DKI \), and \( EKJ \) are a...
3840
0
7,927.625
-1
7,927.625
Suppose that 9 boys and 15 girls line up in a row, but the arrangement must start with a boy and end with a girl. Let $T$ be the number of places in the row where a boy and a girl are standing next to each other. Calculate the average value of $T$ when all possible orders of these 24 people under the given conditions a...
12
0
7,469.4375
-1
7,469.4375
Find all prime numbers $p$ for which there exists a unique $a \in\{1,2, \ldots, p\}$ such that $a^{3}-3 a+1$ is divisible by $p$.
3
We show that $p=3$ is the only prime that satisfies the condition. Let $f(x)=x^{3}-3 x+1$. As preparation, let's compute the roots of $f(x)$. By Cardano's formula, it can be seen that the roots are $2 \operatorname{Re} \sqrt[3]{\frac{-1}{2}+\sqrt{\left(\frac{-1}{2}\right)^{2}-\left(\frac{-3}{3}\right)^{3}}}=2 \operator...
0
8,192
-1
8,192
Let $n$ be a positive integer. E. Chen and E. Chen play a game on the $n^2$ points of an $n \times n$ lattice grid. They alternately mark points on the grid such that no player marks a point that is on or inside a non-degenerate triangle formed by three marked points. Each point can be marked only once. The game ...
1007
0.4375
7,254.625
6,532.285714
7,816.444444
Complex numbers \(a\), \(b\), \(c\) form an equilateral triangle with side length 24 in the complex plane. If \(|a + b + c| = 48\), find \(|ab + ac + bc|\).
768
0.125
8,163.5625
7,964.5
8,192
Given the equation about $x$, $2x^{2}-( \sqrt {3}+1)x+m=0$, its two roots are $\sin θ$ and $\cos θ$, where $θ∈(0,π)$. Find: $(1)$ the value of $m$; $(2)$ the value of $\frac {\tan θ\sin θ}{\tan θ-1}+ \frac {\cos θ}{1-\tan θ}$; $(3)$ the two roots of the equation and the value of $θ$ at this time.
\frac {1}{2}
0
6,515.5
-1
6,515.5
How many positive integers less than $101$ are multiples of either $5$ or $7$, but not both at once?
30
0.8125
4,738.3125
3,941.307692
8,192
Andy, Beth, Charlie, and Daniel take a test with thirty questions. Andy and Beth together get the same number of questions wrong as Charlie and Daniel together. Andy and Daniel together get four more questions wrong than Beth and Charlie do together. If Charlie gets five questions wrong, how many questions does Andy ge...
7
1
1,930.25
1,930.25
-1
Let $\mathbf{v}$ be a vector such that \[\left\| \mathbf{v} + \begin{pmatrix} 3 \\ -1 \end{pmatrix} \right\| = 8.\]Find the smallest possible value of $\|\mathbf{v}\|.$
8 - \sqrt{10}
0.6875
6,619.3125
5,904.454545
8,192
A leak formed in the hold of a ship. A pump was immediately switched on to remove the water, but it couldn't keep up, and after 10 minutes, the water level rose by 20 cm. Then, a second pump of equal power was turned on, and after 5 minutes, the water level dropped by 10 cm. The leak was then sealed. How much time wil...
1.25
0
8,061.75
-1
8,061.75
Let $\triangle A B C$ be a triangle with $A B=7, B C=1$, and $C A=4 \sqrt{3}$. The angle trisectors of $C$ intersect $\overline{A B}$ at $D$ and $E$, and lines $\overline{A C}$ and $\overline{B C}$ intersect the circumcircle of $\triangle C D E$ again at $X$ and $Y$, respectively. Find the length of $X Y$.
\frac{112}{65}
Let $O$ be the cirumcenter of $\triangle C D E$. Observe that $\triangle A B C \sim \triangle X Y C$. Moreover, $\triangle A B C$ is a right triangle because $1^{2}+(4 \sqrt{3})^{2}=7^{2}$, so the length $X Y$ is just equal to $2 r$, where $r$ is the radius of the circumcircle of $\triangle C D E$. Since $D$ and $E$ ar...
0.875
6,509.8125
6,269.5
8,192
Let \[\bold{A} = \begin{pmatrix} 0 & 1 & 2 \\ 1 & 0 & 1 \\ 2 & 1 & 0 \end{pmatrix}.\]There exist constants $p$, $q$, and $r$ such that \[\bold{A}^3 + p \bold{A}^2 + q \bold{A} + r \bold{I} = \bold{0},\]where $\bold{I}$ and $\bold{0}$ are the $3 \times 3$ identity matrix and zero matrix, respectively. Enter the ordered...
(0,-6,-4)
0.3125
7,572.0625
6,208.2
8,192
How many pairs of two-digit positive integers have a difference of 50?
40
0.4375
7,198.4375
6,375.285714
7,838.666667
The sequence $\{a_i\}_{i \ge 1}$ is defined by $a_1 = 1$ and \[ a_n = \lfloor a_{n-1} + \sqrt{a_{n-1}} \rfloor \] for all $n \ge 2$ . Compute the eighth perfect square in the sequence. *Proposed by Lewis Chen*
64
0.0625
7,991.25
4,980
8,192
In the two-dimensional rectangular coordinate system, given the vector $\overrightarrow{a}=(-1,2)$, and points $A(8,0)$, $B(n,t)$, $C(k\sin θ,t)(0≤θ≤\frac {π}{2})$. (1) If $\overrightarrow{AB} \perp \overrightarrow{a}$, and $|\overrightarrow{AB}|= \sqrt {5}|\overrightarrow{OA}|(O$ is the origin$)$, find the vector $\ov...
32
0.25
6,538.8125
5,852.5
6,767.583333
A teacher intends to give the children a problem of the following type. He will tell them that he has thought of a polynomial \( P(x) \) of degree 2017 with integer coefficients and a leading coefficient of 1. Then he will provide them with \( k \) integers \( n_{1}, n_{2}, \ldots, n_{k} \), and separately provide the ...
2017
0
8,085.25
-1
8,085.25
Represent the number 1000 as a sum of the maximum possible number of natural numbers, the sums of the digits of which are pairwise distinct.
19
0
8,192
-1
8,192
Given the function $f(x)=x- \frac {1}{x}+2a\ln x$ $(a\in\mathbb{R})$. $(1)$ Discuss the monotonicity of $f(x)$; $(2)$ If $f(x)$ has two extreme values $x_{1}$ and $x_{2}$, where $x_{2}\in[e,+\infty)$, find the minimum value of $f(x_{1})-f(x_{2})$.
\frac {4}{e}
0.125
8,078
7,280
8,192
If a number is a multiple of 4 or contains the digit 4, we say this number is a "4-inclusive number", such as 20, 34. Arrange all "4-inclusive numbers" in the range \[0, 100\] in ascending order to form a sequence. What is the sum of all items in this sequence?
1883
0
8,099.3125
-1
8,099.3125
Given vectors $\overrightarrow{a}=(2\cos\omega x,-2)$ and $\overrightarrow{b}=(\sqrt{3}\sin\omega x+\cos\omega x,1)$, where $\omega\ \ \gt 0$, and the function $f(x)=\overrightarrow{a}\cdot\overrightarrow{b}+1$. The distance between two adjacent symmetric centers of the graph of $f(x)$ is $\frac{\pi}{2}$. $(1)$ Find ...
\frac{3-\sqrt{3}}{4}
0
7,570.125
-1
7,570.125
At an old estate, the house is surrounded in a circle by tall trees: spruces, pines, and birches. There are a total of 96 trees. These trees have a strange property: from any coniferous tree, if you take two trees skipping one tree in between, one of them is coniferous and the other is deciduous; and from any coniferou...
32
0.0625
7,815.8125
6,934
7,874.6
If $\frac{\sin\theta + \cos\theta}{\sin\theta - \cos\theta} = 2$, calculate the value of $\sin\theta \cdot \cos\theta$.
\frac{3}{10}
1
2,979.3125
2,979.3125
-1
When the polynomial $x^4 - 6x^3 + 16x^ 2 - 25x + 10$ is divided by $x^2 - 2x + k,$ the remainder is $x + a.$ Enter the ordered pair $(k,a).$
(5,-5)
0.6875
4,952.6875
4,454.636364
6,048.4
Let an integer be such that when divided by 20, the remainder is 11. What is the sum of the remainders when the same integer is divided by 4 and by 5? Additionally, find the smallest such integer greater than 50.
51
0.875
1,730.5
1,875.071429
718.5
Given that \(x\) satisfies \(\log _{5x} (2x) = \log _{625x} (8x)\), find the value of \(\log _{2} x\).
\frac{\ln 5}{2 \ln 2 - 3 \ln 5}
0
8,192
-1
8,192
Six balls, numbered 2, 3, 4, 5, 6, 7, are placed in a hat. Each ball is equally likely to be chosen. If one ball is chosen, what is the probability that the number on the selected ball is a prime number?
\frac{2}{3}
1
1,334.4375
1,334.4375
-1
A street has 20 houses on each side, for a total of 40 houses. The addresses on the south side of the street form an arithmetic sequence, as do the addresses on the north side of the street. On the south side, the addresses are 4, 10, 16, etc., and on the north side they are 3, 9, 15, etc. A sign painter paints house n...
84
0.125
6,855.5625
5,409.5
7,062.142857
Workshop A and Workshop B together have 360 workers. The number of workers in Workshop A is three times that of Workshop B. How many workers are there in each workshop?
270
0.125
435.125
443
434
Let the complex number \( z = \cos \frac{2\pi}{13} + i \sin \frac{2\pi}{13} \). Find the value of \( \left(z^{-12} + z^{-11} + z^{-10}\right)\left(z^{3} + 1\right)\left(z^{6} + 1\right) \).
-1
0.3125
7,467.9375
5,875
8,192
Given that the terminal side of angle θ passes through point P(-x, -6) and $$cosθ=- \frac {5}{13}$$, find the value of $$tan(θ+ \frac {π}{4})$$.
-\frac {17}{7}
0.8125
4,474.6875
4,034.923077
6,380.333333
If $\lceil{\sqrt{x}}\rceil=12$, how many possible integer values of $x$ are there?
25
0.0625
5,088.75
1,376
5,336.266667
Two positive integers that only have 1 as a common factor are called coprime numbers. For example, 2 and 7 are coprime, as are 3 and 4. In any permutation of 2, 3, 4, 5, 6, 7, where each pair of adjacent numbers are coprime, there are a total of \_\_\_\_\_\_\_\_ different permutations (answer with a number).
72
0
8,192
-1
8,192
An ATM password at Fred's Bank is composed of four digits from $0$ to $9$, with repeated digits allowable. If no password may begin with the sequence $9,1,1,$ then how many passwords are possible?
9990
To find the total number of possible ATM passwords, we need to consider the constraints given in the problem. The password is a four-digit number, where each digit can range from $0$ to $9$. However, the password cannot begin with the sequence $9,1,1$. **Step 1: Calculate the total number of unrestricted passwords.**...
1
3,784.125
3,784.125
-1
In the right circular cone $P-ABC$, $PA \perp$ plane $ABC$, $AC \perp AB$, $PA=AB=2$, $AC=1$. Find the volume of the circumscribed sphere of the cone $P-ABC$.
\frac{9}{2}\pi
0.9375
4,526.125
4,281.733333
8,192
In the Cartesian coordinate system, with the origin as the pole and the positive half-axis of the x-axis as the polar axis, a polar coordinate system is established. The polar equation of line $l$ is $\rho\cos(\theta+ \frac{\pi}{4})= \frac{\sqrt{2}}{2}$, and the parametric equation of curve $C$ is $\begin{cases} x=5+\c...
\sqrt{34}+2
0.0625
7,830.6875
8,192
7,806.6
In quadrilateral $ABCD$, $\angle{BAD}\cong\angle{ADC}$ and $\angle{ABD}\cong\angle{BCD}$, $AB = 8$, $BD = 10$, and $BC = 6$. The length $CD$ may be written in the form $\frac {m}{n}$, where $m$ and $n$ are relatively prime positive integers. Find $m + n$.
69
Draw a line from $B$, parallel to $\overline{AD}$, and let it meet $\overline{CD}$ at $M$. Note that $\triangle{DAB}$ is similar to $\triangle{BMC}$ by AA similarity, since $\angle{ABD}=\angle{MCB}$ and since $BM$ is parallel to $CD$ then $\angle{BMC}=\angle{ADM}=\angle{DAB}$. Now since $ADMB$ is an isosceles trapezoid...
0
7,982.375
-1
7,982.375
When Dave walks to school, he averages $90$ steps per minute, and each of his steps is $75$ cm long. It takes him $16$ minutes to get to school. His brother, Jack, going to the same school by the same route, averages $100$ steps per minute, but his steps are only $60$ cm long. How long does it take Jack to get to schoo...
18 minutes
1. **Calculate Dave's walking speed**: Dave walks at a rate of $90$ steps per minute, with each step being $75$ cm long. Therefore, his walking speed is: \[ 90 \text{ steps/min} \times 75 \text{ cm/step} = 6750 \text{ cm/min} \] 2. **Calculate the distance to school**: It takes Dave $16$ minutes to ...
0
3,846.0625
-1
3,846.0625
Let \( A_0 = (0,0) \). Points \( A_1, A_2, \dots \) lie on the \( x \)-axis, and distinct points \( B_1, B_2, \dots \) lie on the graph of \( y = x^2 \). For every positive integer \( n \), \( A_{n-1}B_nA_n \) is an equilateral triangle. What is the least \( n \) for which the length \( A_0A_n \geq 100 \)?
10
0
8,056
-1
8,056
Let $S=(x-1)^4+4(x-1)^3+6(x-1)^2+4(x-1)+1$. Then $S$ equals:
x^4
1. **Substitute $y = x - 1$ into $S$:** \[ S = (x-1)^4 + 4(x-1)^3 + 6(x-1)^2 + 4(x-1) + 1 \] Replace $x-1$ with $y$: \[ S = y^4 + 4y^3 + 6y^2 + 4y + 1 \] 2. **Recognize the pattern in $S$:** The expression $S = y^4 + 4y^3 + 6y^2 + 4y + 1$ resembles the expansion of a binomial raised to the four...
0.9375
2,494
2,114.133333
8,192
If a number $N, N \ne 0$, diminished by four times its reciprocal, equals a given real constant $R$, then, for this given $R$, the sum of all such possible values of $N$ is
R
1. **Formulate the Equation**: Given that a number $N$, diminished by four times its reciprocal, equals a real constant $R$, we can write the equation as: \[ N - \frac{4}{N} = R. \] 2. **Manipulate the Equation**: To eliminate the fraction, multiply through by $N$ (assuming $N \neq 0$): \[ N^2 - 4 = RN...
1
1,948.4375
1,948.4375
-1
Evaluate the expression \[ \frac{a+2}{a+1} \cdot \frac{b-1}{b-2} \cdot \frac{c + 8}{c+6} , \] given that $c = b-10$, $b = a+2$, $a = 4$, and none of the denominators are zero.
3
1
2,332.5
2,332.5
-1
Sasha and Misha are playing a game: they take turns naming a number from 1 to 213 (Misha goes first, and the numbers must be different). Then each counts the number of different rectangles with integer sides whose perimeter equals the named number. The one with the greater number of rectangles wins. What number should...
212
0.375
7,198
5,541.333333
8,192
The sequence $\{a_n\}$ satisfies $a_1=1$, $a_2=1$, $a_{n+2}=(1+\sin^2 \frac{n\pi}{2})a_n+2\cos^2 \frac{n\pi}{2}$. Find the sum of the first $20$ terms of this sequence.
1123
0.75
6,697.6875
6,199.583333
8,192
In which acute-angled triangle is the value of the product \(\operatorname{tg} \alpha \cdot \operatorname{tg} \beta \cdot \operatorname{tg} \gamma\) minimized?
\sqrt{27}
0
7,049.0625
-1
7,049.0625
Consider a regular tetrahedron $ABCD$. Find $\sin \angle BAC$.
\frac{2\sqrt{2}}{3}
0
6,691.6875
-1
6,691.6875
For the nonzero numbers $a$, $b$, and $c$, define $$ \text{{J}}(a,b,c) = \frac{a}{b} + \frac{b}{c} + \frac{c}{a}. $$Find $\text{{J}}(2,12, 9)$.
6
1
2,405.875
2,405.875
-1
How many integer values of $n$ satisfy $-50 < n^3 < 50$?
7
1
3,130.25
3,130.25
-1
Two candidates participated in an election with \(p+q\) voters. Candidate \(A\) received \(p\) votes and candidate \(B\) received \(q\) votes, with \(p > q\). During the vote counting, only one vote is registered at a time on a board. Let \(r\) be the probability that the number associated with candidate \(A\) on the ...
\frac{1}{2019}
0.75
4,466.3125
3,224.416667
8,192
Alec wishes to construct a string of 6 letters using the letters A, C, G, and N, such that: - The first three letters are pairwise distinct, and so are the last three letters; - The first, second, fourth, and fifth letters are pairwise distinct. In how many ways can he construct the string?
96
There are $4!=24$ ways to decide the first, second, fourth, and fifth letters because these letters can be selected sequentially without replacement from the four possible letters. Once these four letters are selected, there are 2 ways to select the third letter because two distinct letters have already been selected f...
0
8,192
-1
8,192
A cube with side length $1$ is sliced by a plane that passes through two diagonally opposite vertices $A$ and $C$ and the midpoints $B$ and $D$ of two opposite edges not containing $A$ or $C$, as shown. What is the area of quadrilateral $ABCD$?
\frac{\sqrt{6}}{2}
1. **Identify the Shape of Quadrilateral $ABCD$**: - The cube has side length $1$. - Vertices $A$ and $C$ are diagonally opposite in the cube, making $AC$ a space diagonal. - Points $B$ and $D$ are midpoints of two opposite edges not containing $A$ or $C$. - Since $B$ and $D$ are midpoints, each segment fro...
0
7,602.75
-1
7,602.75
The mean (average) of 6, 9 and 18 is equal to the mean (average) of 12 and $y$. What is the value of $y$?
10
1
1,072.625
1,072.625
-1
Evaluate the determinant of the given matrix: \[ \begin{vmatrix} \sin \theta \sin \phi & \sin \theta \cos \phi & \cos \theta \\ \cos \phi & -\sin \phi & 0 \\ -\cos \theta \sin \phi & -\cos \theta \cos \phi & \sin \theta \end{vmatrix} \]
-1
0.25
7,370.8125
4,907.25
8,192
In the equation $$ \frac{x^{2}+p}{x}=-\frac{1}{4}, $$ with roots \(x_{1}\) and \(x_{2}\), determine \(p\) such that: a) \(\frac{x_{1}}{x_{2}}+\frac{x_{2}}{x_{1}}=-\frac{9}{4}\), b) one root is 1 less than the square of the other root.
-\frac{15}{8}
0.375
7,187.5
6,004.166667
7,897.5
In order to compute the area of a particular circle, Juan first measures the length of its diameter. The actual diameter is 20 cm, but Juan's measurement has an error of up to $20\%$. What is the largest possible percent error, in percent, in Juan's computed area of the circle?
44
1
3,262.5
3,262.5
-1
Given that the function $F(x) = f(x) + x^2$ is an odd function, and $f(2) = 1$, find $f(-2)$.
-9
1
1,941.875
1,941.875
-1
Business is a little slow at Lou's Fine Shoes, so Lou decides to have a sale. On Friday, Lou increases all of Thursday's prices by $10$ percent. Over the weekend, Lou advertises the sale: "Ten percent off the listed price. Sale starts Monday." How much does a pair of shoes cost on Monday that cost $40$ dollars on Thurs...
39.60
1. **Calculate the price increase on Friday:** The price of the shoes on Thursday is $40$ dollars. On Friday, Lou increases the prices by $10\%$. Therefore, the price on Friday can be calculated as follows: \[ \text{Price on Friday} = \text{Price on Thursday} \times (1 + 10\%) = 40 \times 1.1 = 44 \text{ dolla...
1
2,311.3125
2,311.3125
-1
In the Cartesian coordinate plane $(xOy)$, given vectors $\overrightarrow{AB}=(6,1)$, $\overrightarrow{BC}=(x,y)$, $\overrightarrow{CD}=(-2,-3)$, and $\overrightarrow{AD}$ is parallel to $\overrightarrow{BC}$. (1) Find the relationship between $x$ and $y$; (2) If $\overrightarrow{AC}$ is perpendicular to $\overrightarr...
16
0.875
4,772.125
4,283.571429
8,192
Compute $\begin{pmatrix} \sqrt{3} & -1 \\ 1 & \sqrt{3} \end{pmatrix}^6.$
\begin{pmatrix} -64 & 0 \\ 0 & -64 \end{pmatrix}
0.5625
7,006.5
6,482
7,680.857143
Given sets $A=\{1, 2, 3, 4\}$, $B=\{5, 6, 7\}$, and $C=\{8, 9\}$. Now, take any two sets from these three sets, and then pick one element from each of the two selected sets to form a new set with two elements. The total number of distinct sets that can be formed is $\_\_\_\_\_\_\_\_$.
26
0.8125
4,954.6875
4,207.615385
8,192
Let $S$ be the set of integers $n > 1$ for which $\tfrac1n = 0.d_1d_2d_3d_4\ldots$, an infinite decimal that has the property that $d_i = d_{i+12}$ for all positive integers $i$. Given that $9901$ is prime, how many positive integers are in $S$? (The $d_i$ are digits.)
255
0.125
7,653
4,452
8,110.285714
In triangle $\triangle ABC$, the sides opposite angles $A$, $B$, and $C$ are $a$, $b$, and $c$ respectively. Given that $2a\sin B= \sqrt{3}b$ and $\cos C = \frac{5}{13}$: (1) Find the value of $\sin A$; (2) Find the value of $\cos B$.
\frac{12\sqrt{3} - 5}{26}
0
7,336.75
-1
7,336.75
Suppose $\cos Q = 0.4$ in the diagram below. What is $QR$? [asy] pair P,Q,R; P = (0,0); Q = (6,0); R = (0,6*tan(acos(0.4))); draw(P--Q--R--P); draw(rightanglemark(Q,P,R,18)); label("$P$",P,SW); label("$Q$",Q,SE); label("$R$",R,N); label("$12$",Q/2,S); [/asy]
30
0.5
1,913
1,398.75
2,427.25
Express as a common fraction in simplest form: $$ \sqrt{6\frac{1}{4}} $$
\frac{5}{2}
1
1,389.5
1,389.5
-1
A box contains 5 white balls and 5 black balls. I draw them out of the box, one at a time. What is the probability that all of my draws alternate colors, starting and ending with the same color?
\frac{1}{126}
0.375
6,800.9375
5,459.5
7,605.8
Use the bisection method to find an approximate zero of the function $f(x) = \log x + x - 3$, given that approximate solutions (accurate to 0.1) are $\log 2.5 \approx 0.398$, $\log 2.75 \approx 0.439$, and $\log 2.5625 \approx 0.409$.
2.6
0
8,192
-1
8,192
In a bag of marbles, $\frac{3}{5}$ of the marbles are blue and the rest are red. If the number of red marbles is doubled and the number of blue marbles stays the same, what fraction of the marbles will be red?
\frac{4}{7}
1. **Identify the fraction of blue and red marbles initially:** Let the total number of marbles be $x$. Given that $\frac{3}{5}$ of the marbles are blue, the number of blue marbles is $\frac{3}{5}x$. The rest of the marbles are red, so the number of red marbles is $x - \frac{3}{5}x = \frac{2}{5}x$. 2. **Double the ...
1
1,981.3125
1,981.3125
-1
Let vectors $\overrightarrow{a_{1}}=(1,5)$, $\overrightarrow{a_{2}}=(4,-1)$, $\overrightarrow{a_{3}}=(2,1)$, and let $\lambda_{1}, \lambda_{2}, \lambda_{3}$ be non-negative real numbers such that $\lambda_{1}+\frac{\lambda_{2}}{2}+\frac{\lambda_{3}}{3}=1$. Find the minimum value of $\left|\lambda_{1} \overrightarrow{a_...
3\sqrt{2}
0
8,090.8125
-1
8,090.8125
Bricklayer Brenda would take $9$ hours to build a chimney alone, and bricklayer Brandon would take $10$ hours to build it alone. When they work together they talk a lot, and their combined output is decreased by $10$ bricks per hour. Working together, they build the chimney in $5$ hours. How many bricks are in the chim...
900
1. **Define Variables:** Let $h$ be the total number of bricks in the chimney. 2. **Individual Rates:** - Brenda's rate of laying bricks is $\frac{h}{9}$ bricks per hour. - Brandon's rate of laying bricks is $\frac{h}{10}$ bricks per hour. 3. **Combined Rate with Decreased Output:** When Brenda and Brando...
1
1,937.1875
1,937.1875
-1