problem
stringlengths
10
5.15k
answer
stringlengths
0
1.22k
solution
stringlengths
0
11.1k
reward
float64
0
1
length
float64
172
8.19k
correct_length
float64
-1
8.19k
incorrect_length
float64
-1
8.19k
In △ABC, the sides opposite to angles A, B, C are a, b, c, respectively. Given cosB= $\frac {2}{5}$, and sinAcosB - (2c - cosA)•sinB = 0. (1) Find the value of b; (2) Find the maximum value of the perimeter of △ABC.
\frac { \sqrt {30}}{6} + \frac {1}{2}
0
7,637.375
-1
7,637.375
Let $\mathcal{P}$ be a regular $2022$ -gon with area $1$ . Find a real number $c$ such that, if points $A$ and $B$ are chosen independently and uniformly at random on the perimeter of $\mathcal{P}$ , then the probability that $AB \geq c$ is $\tfrac{1}{2}$ . *Espen Slettnes*
\sqrt{2/\pi}
0
6,908.625
-1
6,908.625
At what angle to the x-axis is the tangent to the graph of the function \( g(x) = x^2 \ln x \) inclined at the point \( x_0 = 1 \)?
\frac{\pi}{4}
0.875
2,012.75
2,026
1,920
9 kg of toffees cost less than 10 rubles, and 10 kg of the same toffees cost more than 11 rubles. How much does 1 kg of these toffees cost?
1.11
0.0625
1,055.5625
556
1,088.866667
Bob rolls a fair six-sided die each morning. If Bob rolls a composite number, he eats sweetened cereal. If he rolls a prime number, he eats unsweetened cereal. If he rolls a 1, then he rolls again. In a non-leap year, what is the expected number of times Bob will roll his die?
438
0.5
4,221.1875
3,271.125
5,171.25
Let $b$ and $c$ be real numbers. If the polynomial $x^2+bx+c$ has exactly one real root and $b=c+1$, find the value of the product of all possible values of $c$.
1
1
2,672.8125
2,672.8125
-1
A palindrome is a number that reads the same forwards and backwards, such as 3003. How many positive four-digit integers are palindromes?
90
0.9375
2,321.3125
1,929.933333
8,192
Set $u_0 = \frac{1}{4}$, and for $k \ge 0$ let $u_{k+1}$ be determined by the recurrence \[u_{k+1} = 2u_k - 2u_k^2.\]This sequence tends to a limit; call it $L$. What is the least value of $k$ such that \[|u_k-L| \le \frac{1}{2^{1000}}?\]
10
1. **Define the sequence and transformation**: Given the recurrence relation: \[ u_{k+1} = 2u_k - 2u_k^2 \] We start with $u_0 = \frac{1}{4}$. To simplify the recurrence relation, we perform a transformation by defining $v_k = 2u_k - 1$. Substituting $u_k = \frac{v_k + 1}{2}$ into the recurrence relation, w...
0.6875
7,463
7,131.636364
8,192
The function $f$ takes nonnegative integers to real numbers, such that $f(1) = 1,$ and \[f(m + n) + f(m - n) = \frac{f(2m) + f(2n)}{2}\]for all nonnnegative integers $m \ge n.$ Find the sum of all possible values of $f(10).$
100
0.8125
6,045.6875
5,550.384615
8,192
The arithmetic mean, geometric mean, and harmonic mean of $a$, $b$, $c$ are $8$, $5$, $3$ respectively. What is the value of $a^2+b^2+c^2$?
326
0.9375
3,728.3125
3,430.733333
8,192
Triangle $ABC$ has $\angle BAC = 60^{\circ}$, $\angle CBA \leq 90^{\circ}$, $BC=1$, and $AC \geq AB$. Let $H$, $I$, and $O$ be the orthocenter, incenter, and circumcenter of $\triangle ABC$, respectively. Assume that the area of pentagon $BCOIH$ is the maximum possible. What is $\angle CBA$?
80^{\circ}
1. **Define the angles and known values**: Let $\angle CAB = A = 60^\circ$, $\angle ABC = B$, and $\angle BCA = C$. We know $BC = 1$ and $AC \geq AB$. 2. **Properties of triangle centers**: - $\angle BOC = 2A = 120^\circ$ (Central angle is twice the inscribed angle). - $\angle BIC = 90^\circ + \frac{A}{2} = 90^...
0
8,192
-1
8,192
In the line $5x + 8y + c = 0$, the sum of the $x$- and $y$-intercepts is $26$. Find $c$.
-80
1
2,344
2,344
-1
The circumradius R of triangle △ABC is $\sqrt{3}$. The sides opposite to angles A, B, and C are a, b, c respectively, and it is given that $\frac{2\sin A-\sin C}{\sin B} = \frac{\cos C}{\cos B}$. (1) Find the angle B and the side length b. (2) Find the maximum value of the area $S_{\triangle ABC}$ and the values of...
\frac{9\sqrt{3}}{4}
0
6,078.125
-1
6,078.125
Given a connected simple graph \( G \) with \( e \) edges and pieces placed on each vertex of \( G \) (where each piece can only be placed on a single vertex of \( G \)), you are allowed to perform the following operation: if the number of pieces on a vertex \( v \) is at least the number of vertices adjacent to \( v \...
e
0
8,078
-1
8,078
The base and one side of a triangle are 30 and 14, respectively. Find the area of this triangle if the median drawn to the base is 13.
168
1
4,893.4375
4,893.4375
-1
A regular hexagon is inscribed in an equilateral triangle. If the hexagon has an area of 12, what is the area of the equilateral triangle?
18
0.4375
7,361.4375
6,293.571429
8,192
Given that the sequence $\{a\_n\}$ is a positive arithmetic sequence satisfying $\frac{1}{a\_1} + \frac{4}{a\_{2k-1}} \leqslant 1$ (where $k \in \mathbb{N}^*$, and $k \geqslant 2$), find the minimum value of $a\_k$.
\frac{9}{2}
0.6875
6,148.1875
5,396.181818
7,802.6
In triangle ABC, the lengths of the three sides are three consecutive natural numbers, and the largest angle is twice the smallest angle. Calculate the area of this triangle.
\frac {15 \sqrt {7}}{4}
0
6,311.0625
-1
6,311.0625
Find the number of eight-digit numbers whose product of digits equals 1400. The answer must be presented as an integer.
5880
0
8,192
-1
8,192
Given that $\overrightarrow {a}|=4$, $\overrightarrow {e}$ is a unit vector, and the angle between $\overrightarrow {a}$ and $\overrightarrow {e}$ is $\frac {2π}{3}$, find the projection of $\overrightarrow {a}+ \overrightarrow {e}$ on $\overrightarrow {a}- \overrightarrow {e}$.
\frac {5 \sqrt {21}}{7}
0
4,696.625
-1
4,696.625
In parallelogram $ABCD$, $AB = 38$ cm, $BC = 3y^3$ cm, $CD = 2x +4$ cm, and $AD = 24$ cm. What is the product of $x$ and $y$?
34
1
915.875
915.875
-1
If $x y=5$ and $x^{2}+y^{2}=21$, compute $x^{4}+y^{4}$.
391
We have $441=\left(x^{2}+y^{2}\right)^{2}=x^{4}+y^{4}+2(x y)^{2}=x^{4}+y^{4}+50$, yielding $x^{4}+y^{4}=391$.
1
1,588.75
1,588.75
-1
What is the smallest positive integer $n$ such that $531n \equiv 1067n \pmod{24}?$
3
1
2,644.125
2,644.125
-1
A systematic sampling method is used to select 5 representatives from 752 students, after removing 2 students randomly. Calculate the probability that student A is selected.
\frac{5}{752}
0.1875
7,514.6875
6,978
7,638.538462
Seven balls are numbered 1 through 7 and placed in a bowl. Josh will randomly choose a ball from the bowl, look at its number, and then put it back into the bowl. Then Josh will again randomly choose a ball from the bowl and look at its number. What is the probability that the product of the two numbers will be odd and...
\frac{6}{49}
0.9375
4,593.25
4,628.266667
4,068
In the Cartesian coordinate system $xOy$, the parametric equation of line $l$ is $$ \begin{cases} x = -1 + \frac {\sqrt {2}}{2}t \\ y = 1 + \frac {\sqrt {2}}{2}t \end{cases} (t \text{ is the parameter}), $$ and the equation of circle $C$ is $(x-2)^{2} + (y-1)^{2} = 5$. Establish a polar coordinate system with the origi...
\frac{3\sqrt{10}}{10}
0
5,626.375
-1
5,626.375
What is $\frac{2^3 + 2^3}{2^{-3} + 2^{-3}}$?
64
1. **Simplify the Numerator and Denominator**: The given expression is: \[ \frac{2^3 + 2^3}{2^{-3} + 2^{-3}} \] We can factor out the common terms in both the numerator and the denominator: \[ \frac{2 \cdot 2^3}{2 \cdot 2^{-3}} = \frac{2 \times 8}{2 \times \frac{1}{8}} \] Simplifying further...
1
1,825.75
1,825.75
-1
Let $w$, $x$, $y$, and $z$ be whole numbers. If $2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$, then what does $2w + 3x + 5y + 7z$ equal?
21
1. **Prime Factorization of 588**: To solve for $w$, $x$, $y$, and $z$, we first need to find the prime factorization of 588. We start by dividing 588 by the smallest prime numbers until we reach 1: \[ 588 \div 2 = 294, \quad 294 \div 2 = 147, \quad 147 \div 3 = 49, \quad 49 \div 7 = 7, \quad 7 \div 7 = 1 \...
1
1,698.625
1,698.625
-1
Find all real solutions to $x^3+(x+1)^3+(x+2)^3=(x+3)^3$. Enter all the solutions, separated by commas.
3
1
3,433.5625
3,433.5625
-1
Among all the roots of \[z^8 - z^6 + z^4 - z^2 + 1 = 0,\]the maximum imaginary part of a root can be expressed as $\sin \theta,$ where $-90^\circ \le \theta \le 90^\circ.$ Find $\theta.$
54^\circ
0.25
7,589.0625
6,802.75
7,851.166667
Find $\begin{pmatrix} 2 \\ -5 \end{pmatrix} - 4 \begin{pmatrix} -1 \\ 7 \end{pmatrix}.$
\begin{pmatrix} 6 \\ -33 \end{pmatrix}
0.9375
2,006.0625
1,898.266667
3,623
How many two-digit numbers have digits whose sum is a prime number?
35
0
6,885.25
-1
6,885.25
A car left the city for the village, and simultaneously, a cyclist left the village for the city. When the car and the cyclist met, the car immediately turned around and went back to the city. As a result, the cyclist arrived in the city 35 minutes later than the car. How many minutes did the cyclist spend on the entir...
55
0.1875
6,381.75
3,698
7,001.076923
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 $1000$.
440
As mentioned in solution one, for the difference of two complex numbers to be real, their imaginary parts must be equal. We use exponential form of complex numbers. Let $z = e^{i \theta}$. We have two cases to consider. Either $z^{6!} = z^{5!}$, or $z^{6!}$ and $z^{5!}$ are reflections across the imaginary axis. If $z^...
0.25
7,802.125
7,033.5
8,058.333333
Evaluate the expression: \\( \frac {\cos 40 ^{\circ} +\sin 50 ^{\circ} (1+ \sqrt {3}\tan 10 ^{\circ} )}{\sin 70 ^{\circ} \sqrt {1+\cos 40 ^{\circ} }}\\)
\sqrt {2}
0
8,119.875
-1
8,119.875
Let $N$ be the smallest positive integer for which $$x^{2}+x+1 \quad \text { divides } \quad 166-\sum_{d \mid N, d>0} x^{d}$$ Find the remainder when $N$ is divided by 1000.
\[ N \equiv 672 \pmod{1000} \]
Let $\omega=e^{2 \pi i / 3}$. The condition is equivalent to $$166=\sum_{d \mid N, d>0} \omega^{d}$$ Let's write $N=3^{d} n$ where $n$ is not divisible by 3. If all primes dividing $n$ are $1 \bmod 3$, then $N$ has a positive number of factors that are $1 \bmod 3$ and none that are $2 \bmod 3$, so $\sum_{d \mid N, d>0}...
0
8,192
-1
8,192
Given a pedestrian signal light that alternates between red and green, with the red light lasting for 50 seconds, calculate the probability that a student needs to wait at least 20 seconds for the green light to appear.
\dfrac{3}{5}
0.125
6,063
3,848.5
6,379.357143
Calculate the product of $\frac{5}{3} \times \frac{6}{5} \times \frac{7}{6} \times \cdots \times \frac{2010}{2009}$.
670
0.875
3,626.875
2,974.714286
8,192
Let $P(x)$ be a polynomial such that when $P(x)$ is divided by $x-17$, the remainder is $14$, and when $P(x)$ is divided by $x-13$, the remainder is $6$. What is the remainder when $P(x)$ is divided by $(x-13)(x-17)$?
2x-20
1
1,750.25
1,750.25
-1
If $AB$ and $CD$ are perpendicular diameters of circle $Q$, $P$ in $\overline{AQ}$, and $\angle QPC = 60^\circ$, then the length of $PQ$ divided by the length of $AQ$ is
\frac{\sqrt{3}}{3}
1. **Identify the Geometry of the Circle:** Since $AB$ and $CD$ are perpendicular diameters of circle $Q$, they intersect at the center of the circle, which we will denote as $O$. This makes $O$ the midpoint of both $AB$ and $CD$. 2. **Position of Point $P$:** Point $P$ lies on $\overline{AQ}$. Since $AB$ and $...
0
3,799.125
-1
3,799.125
What is the total number of digits used when the first 2500 positive even integers are written?
9444
0.0625
5,278.4375
4,869
5,305.733333
There are 29 ones written on a board. Each minute, Karlson erases any two numbers and writes their sum on the board, then eats a number of candies equal to the product of the two erased numbers. What is the maximum number of candies he could eat in 29 minutes?
406
0.25
8,047.375
7,699.5
8,163.333333
In the sequence $\{a_n\}$, $a_n$ is the closest positive integer to $\sqrt{n}$ ($n \in \mathbb{N}^*$). Compute the sum $\sum_{i=1}^{100}\frac{1}{a_i} = \_\_\_\_\_\_\_\_$.
19
0.3125
7,216.1875
5,889
7,819.454545
Samson writes down the number 123456789 on a piece of paper. He can insert multiplication signs between any two adjacent digits, any number of times at different places, or none at all. By reading the digits between the multiplication signs as individual numbers, he creates an expression made up of the products of thes...
123456789
0
8,192
-1
8,192
How many unordered pairs of edges of a given square pyramid determine a plane?
18
0.1875
7,553.875
6,366
7,828
Given that $\tan \alpha = 2$, find the value of $\frac{2 \sin \alpha - \cos \alpha}{\sin \alpha + 2 \cos \alpha}$.
\frac{3}{4}
1
2,447.4375
2,447.4375
-1
What is the least positive integer with exactly $12$ positive factors?
60
0.9375
3,820
3,528.533333
8,192
Given that the domains of functions $f(x)$ and $g(x)$ are both $\mathbb{R}$, and $f(x) + g(2-x) = 5$, $g(x) - f(x-4) = 7$, if the graph of $y=g(x)$ is symmetric about the line $x=2$ and $g(2) = 4$, find $\sum _{k=1}^{22}f(k)$.
-24
0.125
7,435.8125
7,022
7,494.928571
Let \(\mathcal{S}\) be a set of 16 points in the plane, no three collinear. Let \(\chi(\mathcal{S})\) denote the number of ways to draw 8 line segments with endpoints in \(\mathcal{S}\), such that no two drawn segments intersect, even at endpoints. Find the smallest possible value of \(\chi(\mathcal{S})\) across all su...
1430
0.125
7,845.625
6,875
7,984.285714
Given that the terminal side of angle $θ$ is symmetric to the terminal side of a $480^\circ$ angle with respect to the $x$-axis, and point $P(x,y)$ is on the terminal side of angle $θ$ (not the origin), then the value of $\frac{xy}{{x}^2+{y}^2}$ is equal to __.
\frac{\sqrt{3}}{4}
0
4,753.9375
-1
4,753.9375
The numbers from 1 to 9 are divided into three groups of three numbers, and then the numbers in each group are multiplied. $A$ is the largest of the three products. What is the smallest possible value of $A$?
72
0.125
7,960.375
6,339
8,192
Find all ordered pairs $(a, b)$ of positive integers such that $2 a+1$ divides $3 b-1$ and $2 b+1$ divides $3 a-1$.
(2,2),(12,17),(17,12)
This is equivalent to the existence of nonnegative integers $c$ and $d$ such that $3 b-1=c(2 a+1)$ and $3 a-1=d(2 b+1)$. Then $$c d=\frac{(3 b-1)(3 a-1)}{(2 a+1)(2 b+1)}=\frac{3 a-1}{2 a+1} \cdot \frac{3 b-1}{2 b+1}<\frac{3}{2} \cdot \frac{3}{2}=2.25$$ Neither $c$ nor $d$ can equal 0 since that would give $a=\frac{1}{3...
0
7,989.0625
-1
7,989.0625
A nonzero polynomial with rational coefficients has all of the numbers \[1+\sqrt{2}, \; 2+\sqrt{3}, \;3+\sqrt{4},\; \dots, \;1000+\sqrt{1001}\]as roots. What is the smallest possible degree of such a polynomial?
1970
0.3125
5,869.25
6,022.8
5,799.454545
How many positive, three-digit integers contain at least one $3$ as a digit but do not contain a $5$ as a digit?
200
0.5625
6,010.375
4,313.555556
8,192
In a six-digit decimal number $\overline{a_{1} a_{2} a_{3} a_{4} a_{5} a_{6}}$, each digit $a_{i}(1 \leqslant i \leqslant 6)$ is an odd number, and the digit 1 is not allowed to appear consecutively (for example, 135131 and 577797 satisfy the conditions, while 311533 does not satisfy the conditions). Find the total num...
13056
0.25
7,737.3125
6,373.25
8,192
Find the maximum value of \[\cos \theta_1 \sin \theta_2 + \cos \theta_2 \sin \theta_3 + \cos \theta_3 \sin \theta_4 + \cos \theta_4 \sin \theta_5 + \cos \theta_5 \sin \theta_1,\]over all real numbers $\theta_1,$ $\theta_2,$ $\theta_3,$ $\theta_4,$ and $\theta_5.$
\frac{5}{2}
0.25
7,777.625
6,534.5
8,192
What is the sum of $\left(\dfrac{1}{3}\right) + \left(\dfrac{1}{3}\right)^2 + \left(\dfrac{1}{3}\right)^3 + \left(\dfrac{1}{3}\right)^4$?
\dfrac{40}{81}
1
3,439.1875
3,439.1875
-1
For how many integers \( n \) between 1 and 15 (inclusive) is \(\frac{n}{18}\) a repeating decimal?
10
0.0625
5,391.875
2,493
5,585.133333
Given a set of four-ordered real number pairs \((a, b, c, d)\), where \(a, b, c, d \in \{0, 1, 2, 3\}\) and \(a, b, c, d\) can be the same, calculate how many such pairs exist so that \(ad - bc\) is odd.
96
0.3125
7,385.8125
5,612.2
8,192
In the base of the pyramid \( S A B C D \), there is a trapezoid \( A B C D \) with bases \( B C \) and \( A D \), where \( B C = 2 A D \). Points \( K \) and \( L \) are taken on the edges \( S A \) and \( S B \) such that \( 2 S K = K A \) and \( 3 S L = L B \). In what ratio does the plane \( K L C \) divide the edg...
2:1
0.125
7,593.375
4,502.5
8,034.928571
Three points are chosen inside a unit cube uniformly and independently at random. What is the probability that there exists a cube with side length $\frac{1}{2}$ and edges parallel to those of the unit cube that contains all three points?
\frac{1}{8}
Let the unit cube be placed on a $x y z$-coordinate system, with edges parallel to the $x, y, z$ axes. Suppose the three points are labeled $A, B, C$. If there exists a cube with side length $\frac{1}{2}$ and edges parallel to the edges of the unit cube that contain all three points, then there must exist a segment of ...
0
8,153.375
-1
8,153.375
Given a square grid with the letters AMC9 arranged as described, starting at the 'A' in the middle, determine the number of different paths that allow one to spell AMC9 without revisiting any cells.
24
0
7,728.9375
-1
7,728.9375
Given the function $f(x)=x^{2}-2ax+{b}^{2}$, where $a$ and $b$ are real numbers. (1) If $a$ is taken from the set $\{0,1,2,3\}$ and $b$ is taken from the set $\{0,1,2\}$, find the probability that the equation $f(x)=0$ has two distinct real roots. (2) If $a$ is taken from the interval $[0,2]$ and $b$ is taken from the ...
\frac{2}{3}
0.9375
4,856.6875
4,634.333333
8,192
Express $1.\overline{03}$ as a reduced fraction, given that $0.\overline{01}$ is $\frac{1}{99}$.
\frac{34}{33}
1
2,204.25
2,204.25
-1
A doctor told Mikael to take a pill every 75 minutes. He took his first pill at 11:05. At what time did he take his fourth pill?
14:50
0.0625
352
464
344.533333
In triangle $ABC$, where the sides opposite to angles $A$, $B$, and $C$ are denoted as $a$, $b$, and $c$ respectively, it is given that $2 \sqrt {3}ac\sin B = a^{2} + b^{2} - c^{2}$. $(1)$ Determine the size of angle $C$; $(2)$ If $b\sin (\pi - A) = a\cos B$ and $b= \sqrt {2}$, find the area of $\triangle ABC$.
\frac{\sqrt {3} + 1}{4}
0
6,375.125
-1
6,375.125
How many terms of the arithmetic sequence 88, 85, 82, $\dots$ appear before the number $-17$ appears?
35
1
2,787.3125
2,787.3125
-1
Let the function $f(x) = 2\cos^2x + 2\sqrt{3}\sin x\cos x + m$. (1) Find the smallest positive period of the function $f(x)$ and its intervals of monotonic decrease; (2) If $x \in \left[0, \frac{\pi}{2}\right]$, does there exist a real number $m$ such that the range of the function $f(x)$ is exactly $\left[\frac{1}{...
\frac{1}{2}
0.875
6,141.875
5,849
8,192
Let $x$ and $y$ be real numbers, where $y > x > 0$, such that \[ \frac{x}{y} + \frac{y}{x} = 4. \] Find the value of \[ \frac{x + y}{x - y}. \]
\sqrt{3}
0
4,574.125
-1
4,574.125
Determine the number of 6-digit numbers composed of the digits 0, 1, 2, 3, 4, 5 without any repetition and with alternating even and odd digits.
60
0.5
5,807.1875
5,371.375
6,243
A tangent and a secant drawn from the same point to a circle are mutually perpendicular. The length of the tangent is 12, and the internal segment of the secant is 10. Find the radius of the circle.
13
0.25
7,172
4,328.75
8,119.75
In a specific year, a "prime date" occurs when both the month and the day are prime numbers. Determine the total number of prime dates in a non-leap year where February has 28 days, and March, May, and July have 31 days, while November has 30 days.
52
0.4375
4,468.9375
4,258.428571
4,632.666667
Inside the square $A B C D$, a point $P$ is chosen such that the distances from $P$ to vertices $A$, $B$, and $C$ are in the ratio $A P: B P: C P=1: 2: 3$. What is the measure of angle $A P B$?
135
0.75
6,218.9375
5,561.25
8,192
At an elementary school, the students in third grade, fourth grade, and fifth grade run an average of $12$, $15$, and $10$ minutes per day, respectively. There are twice as many third graders as fourth graders, and twice as many fourth graders as fifth graders. What is the average number of minutes run per day by these...
\frac{88}{7}
1. **Define the number of students in each grade**: Let the number of fifth graders be $f$. According to the problem, there are twice as many fourth graders as fifth graders, and twice as many third graders as fourth graders. Therefore, the number of fourth graders is $2f$ and the number of third graders is $4f$. 2...
0.9375
2,652.375
2,675.2
2,310
In rectangle $ABCD$, $P$ is a point on side $\overline{BC}$ such that $BP = 20$ and $CP = 5.$ If $\tan \angle APD = 2,$ then find $AB.$
20
0
7,832.5
-1
7,832.5
What is the largest possible value of the expression $$ gcd \,\,\, (n^2 + 3, (n + 1)^2 + 3 ) $$ for naturals $n$ ? <details><summary>Click to expand</summary>original wording]Kāda ir izteiksmes LKD (n2 + 3, (n + 1)2 + 3) lielākā iespējamā vērtība naturāliem n?</details>
13
0.8125
4,955.3125
4,208.384615
8,192
An equilateral triangle and a circle intersect so that each side of the triangle contains a chord of the circle equal in length to the radius of the circle. What is the ratio of the area of the triangle to the area of the circle? Express your answer as a common fraction in terms of $\pi$.
\frac{9\sqrt{3}}{4\pi}
0
6,420.3125
-1
6,420.3125
Find the minimum value of \[x^2 + 8x + \frac{64}{x^3}\]for $x > 0.$
28
0.875
4,525.5625
4,001.785714
8,192
In the Year 0 of Cambridge there is one squirrel and one rabbit. Both animals multiply in numbers quickly. In particular, if there are $m$ squirrels and $n$ rabbits in Year $k$, then there will be $2 m+2019$ squirrels and $4 n-2$ rabbits in Year $k+1$. What is the first year in which there will be strictly more rabbits...
13
In year $k$, the number of squirrels is $$2(2(\cdots(2 \cdot 1+2019)+2019)+\cdots)+2019=2^{k}+2019 \cdot\left(2^{k-1}+2^{k-2}+\cdots+1\right)=2020 \cdot 2^{k}-2019$$ and the number of rabbits is $$4(4(\cdots(4 \cdot 1-2)-2)-\cdots)-2=4^{k}-2 \cdot\left(4^{k-1}+4^{k-2}+\cdots+1\right)=\frac{4^{k}+2}{3}$$ For the number ...
0.875
6,646.6875
6,425.928571
8,192
Given the function $f(x)=4\cos (3x+φ)(|φ| < \dfrac{π}{2})$, its graph is symmetric about the line $x=\dfrac{11π}{12}$. When $x\_1$, $x\_2∈(−\dfrac{7π}{12},−\dfrac{π}{12})$, $x\_1≠x\_2$, and $f(x\_1)=f(x\_2)$, determine the value of $f(x\_1+x\_2)$.
2\sqrt{2}
0.4375
7,587.625
6,858.142857
8,155
A geometric sequence of positive integers starts with a first term of 4 and the fourth term is 324. What is the fifth term of the sequence?
324
0
8,192
-1
8,192
Two real numbers are selected independently at random from the interval $[-20, 10]$. What is the probability that the product of those numbers is greater than zero?
\frac{5}{9}
1. **Define the intervals for positive and negative numbers**: - The interval $[-20, 10]$ can be split into two parts: $[-20, 0)$ for negative numbers and $(0, 10]$ for positive numbers. - The length of the interval $[-20, 0)$ is $20$ units. - The length of the interval $(0, 10]$ is $10$ units. - The total ...
1
2,622.5625
2,622.5625
-1
How many functions $f:\{0,1\}^{3} \rightarrow\{0,1\}$ satisfy the property that, for all ordered triples \left(a_{1}, a_{2}, a_{3}\right) and \left(b_{1}, b_{2}, b_{3}\right) such that $a_{i} \geq b_{i}$ for all $i, f\left(a_{1}, a_{2}, a_{3}\right) \geq f\left(b_{1}, b_{2}, b_{3}\right)$?
20
Consider the unit cube with vertices $\{0,1\}^{3}$. Let $O=(0,0,0), A=(1,0,0), B=(0,1,0), C=(0,0,1)$, $D=(0,1,1), E=(1,0,1), F=(1,1,0)$, and $P=(1,1,1)$. We want to find a function $f$ on these vertices such that $f(1, y, z) \geq f(0, y, z)$ (and symmetric representations). For instance, if $f(A)=1$, then $f(E)=f(F)=f(...
0.375
6,586.8125
5,280.333333
7,370.7
What is $(a^3+b^3)\div(a^2-ab+b^2+c)$ for $a=7$, $b=6$, and $c=1$?
\frac{559}{44}
0.8125
4,679.125
4,024.846154
7,514.333333
If the product of 6 consecutive odd numbers is 135135, what is the sum of these 6 numbers? $\qquad$
48
0.9375
3,638.6875
3,335.133333
8,192
In the rectangular coordinate system (xOy), a pole coordinate system is established with O as the pole and the positive semi-axis of x as the polar axis. The shortest distance between a point on the curve C: ρcosθ - ρsinθ = 1 and a point on the curve M: x = -2 + cosφ, y = 1 + sinφ (φ is a parameter) can be calculated.
2\sqrt{2}-1
0.625
5,734.375
4,259.8
8,192
Suppose the function $f$ has all real numbers in its domain and range and is invertible. Some values of $f$ are given by the following table: $$\begin{array}{c || c | c | c | c | c} x & 1 & 2 & 3 & 4 & 5 \\ \hline f(x) & 2 & 3 & 5 & 7 & 8 \end{array}$$What is the value of $f(f(3)) + f(f^{-1}(4)) + f^{-1}(f^{-1}(5))?$ I...
14
0.9375
2,849.25
2,737.2
4,530
A circular disk is divided by $2n$ equally spaced radii ($n>0$) and one secant line. The maximum number of non-overlapping areas into which the disk can be divided is
3n+1
To solve this problem, we need to determine how the addition of $2n$ radii and one secant line divides a circular disk into non-overlapping areas. We will analyze the pattern by considering the effect of each additional radius and the secant line. 1. **Base Case Analysis**: - When $n = 0$, there are no radii, and t...
0
8,016
-1
8,016
\(\log _{\sqrt{3}} x+\log _{\sqrt{3}} x+\log _{\sqrt[6]{3}} x+\ldots+\log _{\sqrt{3}} x=36\).
\sqrt{3}
0
8,074.75
-1
8,074.75
In the arithmetic sequence $\{a_n\}$, it is given that $a_{15}+a_{16}+a_{17}=-45$ and $a_{9}=-36$. Let $S_n$ be the sum of the first $n$ terms. $(1)$ Find the minimum value of $S_n$ and the corresponding value of $n$; $(2)$ Calculate $T_n=|a_1|+|a_2|+\cdots+|a_n|$.
-630
0.1875
8,083.375
8,142
8,069.846154
The digit-sum of $998$ is $9+9+8=26$. How many 3-digit whole numbers, whose digit-sum is $26$, are even?
1
To find how many 3-digit whole numbers have a digit-sum of 26 and are even, we start by considering the constraints: 1. **Digit-Sum Requirement**: The sum of the digits of the number must be 26. 2. **Even Number Requirement**: The number must be even, which means its last digit must be an even number (0, 2, 4, 6, or 8...
0.75
6,079.875
5,375.833333
8,192
Consider a 5x5 grid of squares. How many different squares can be traced using the lines in this grid?
55
0.5
6,035.5625
3,879.125
8,192
Let $A_{1}, A_{2}, \ldots, A_{2015}$ be distinct points on the unit circle with center $O$. For every two distinct integers $i, j$, let $P_{i j}$ be the midpoint of $A_{i}$ and $A_{j}$. Find the smallest possible value of $\sum_{1 \leq i<j \leq 2015} O P_{i j}^{2}$.
\frac{2015 \cdot 2013}{4} \text{ OR } \frac{4056195}{4}
Use vectors. $\sum\left|a_{i}+a_{j}\right|^{2} / 4=\sum\left(2+2 a_{i} \cdot a_{j}\right) / 4=\frac{1}{2}\binom{2015}{2}+\frac{1}{4}\left(\left|\sum a_{i}\right|^{2}-\sum\left|a_{i}\right|^{2}\right) \geq 2015 \cdot \frac{2014}{4}-\frac{2015}{4}=\frac{2015 \cdot 2013}{4}$, with equality if and only if $\sum a_{i}=0$, w...
0
8,055.25
-1
8,055.25
Find the remainder when\[\binom{\binom{3}{2}}{2} + \binom{\binom{4}{2}}{2} + \dots + \binom{\binom{40}{2}}{2}\]is divided by $1000$. ~ pi_is_3.14
4
Doing simple algebra calculation will give the following equation: \begin{align*} \binom{\binom{n}{2}}{2} = \frac{\frac{n(n-1)}{2} \cdot (\frac{n(n-1)}{2}-1)}{2} \\ = \frac{n(n-1)(n^2-n-2)}{8} \\ = \frac{(n+1)n(n-1)(n-2)}{8} \\ = \frac{(n+1)!}{8\cdot (n-3)!} = 3 \cdot \frac{(n+1)!}{4!\cdot (n-3)!} \\ = 3 \binom{n+1}{4}...
0.25
7,652.6875
6,034.75
8,192
Given that $F_1$ and $F_2$ are the two foci of the hyperbola $x^2 - \frac{y^2}{24} = 1$, and $P$ is a common point of the hyperbola and the ellipse $\frac{x^2}{49} + \frac{y^2}{24} = 1$, find the area of the triangle $PF_1F_2$.
24
0.9375
4,170.5
4,122
4,898
Coach Grunt is preparing the 5-person starting lineup for his basketball team, the Grunters. There are 12 players on the team. Two of them, Ace and Zeppo, are league All-Stars, so they'll definitely be in the starting lineup. How many different starting lineups are possible? (The order of the players in a basketbal...
120
1
1,821
1,821
-1
The average of a set of data 1, 3, 2, 5, $x$ is 3. What is the standard deviation of this set of data?
\sqrt{2}
1
867.625
867.625
-1
What is the sum of all positive integers $n$ that satisfy $$\mathop{\text{lcm}}[n,120] = \gcd(n,120) + 600~?$$
2520
0
7,745.875
-1
7,745.875
Given a right triangular prism $ABC-A_{1}B_{1}C_{1}$ whose side edge length is equal to the base edge length, find the sine value of the angle formed by $AB_{1}$ and the side face $ACC_{1}A_{1}$.
\frac{\sqrt{6}}{4}
0
6,855.9375
-1
6,855.9375
Let $y=f(x)$ be a quadratic function, and the equation $f(x)=0$ has two equal real roots. Also, $f'(x)=2x+2$. 1. Find the expression for $y=f(x)$. 2. Find the area of the shape enclosed by the graph of $y=f(x)$ and the two coordinate axes. 3. If the line $x=-t$ ($0<t<1$) divides the area enclosed by the graph of $y=f(x...
1-\frac{1}{32}
0
5,756.625
-1
5,756.625