Unnamed: 0
int64
0
40.3k
problem
stringlengths
10
5.15k
ground_truth
stringlengths
1
1.22k
solved_percentage
float64
0
100
25,700
Given in a cube ABCD-A1B1C1D1 with edge length 1, P is a moving point inside the cube (including the surface), if $x + y + z = s$, and $0 \leq x \leq y \leq z \leq 1$, then the volume of the geometric body formed by all possible positions of point P is $\_\_\_\_\_\_\_\_\_\_$.
\frac{1}{6}
79.6875
25,701
Let ellipse M be defined by the equation $$\frac {y^{2}}{a^{2}}+ \frac {x^{2}}{b^{2}}=1$$ where $a>b>0$. The eccentricity of ellipse M and the eccentricity of the hyperbola defined by $x^{2}-y^{2}=1$ are reciprocals of each other, and ellipse M is inscribed in the circle defined by $x^{2}+y^{2}=4$. (1) Find the equation of ellipse M; (2) If the line $y= \sqrt {2}x+m$ intersects ellipse M at points A and B, and there is a point $P(1, \sqrt {2})$ on ellipse M, find the maximum area of triangle PAB.
\sqrt {2}
0
25,702
The digits from 1 to 9 are each used exactly once to write three one-digit integers and three two-digit integers. The one-digit integers are equal to the length, width and height of a rectangular prism. The two-digit integers are equal to the areas of the faces of the same prism. What is the surface area of the rectangular prism?
198
0.78125
25,703
A U-shaped number is a special type of three-digit number where the units digit and the hundreds digit are equal and greater than the tens digit. For example, 818 is a U-shaped number. How many U-shaped numbers are there?
36
1.5625
25,704
Given the function $f(x) = \begin{cases} \log_{10} x, & x > 0 \\ x^{-2}, & x < 0 \end{cases}$, if $f(x\_0) = 1$, find the value of $x\_0$.
10
43.75
25,705
In a factor tree, each value is the product of the two values below it, unless a value is a prime number or a preset integer product of primes. Using this structure, calculate the value of $X$ in the factor tree provided: [asy] draw((-2,-.3)--(0,0)--(2,-.3),linewidth(1)); draw((-3,-1.3)--(-2,-.8)--(-1,-1.3),linewidth(1)); draw((1,-1.3)--(2,-.8)--(3,-1.3),linewidth(1)); label("X",(0,0),N); label("F",(-2,-.8),N); label("7",(-3,-1.3),S); label("G",(2,-.8),N); label("4",(-1,-1.3),S); label("11",(1,-1.3),S); label("H",(3,-1.3),S); draw((-2,-2.3)--(-1,-1.8)--(0,-2.3),linewidth(1)); draw((2,-2.3)--(3,-1.8)--(4,-2.3),linewidth(1)); label("7",(-2,-2.3),S); label("2",(0,-2.3),S); label("11",(2,-2.3),S); label("2",(4,-2.3),S); [/asy]
6776
2.34375
25,706
The area of the ground plane of a truncated cone $K$ is four times as large as the surface of the top surface. A sphere $B$ is circumscribed in $K$ , that is to say that $B$ touches both the top surface and the base and the sides. Calculate ratio volume $B :$ Volume $K$ .
9/14
0.78125
25,707
The number of elderly employees in a sample of 32 young employees from a workplace with a total of 430 employees, 160 of whom are young and the number of middle-aged employees is twice the number of elderly employees, can be found by determining the ratio of young employees in the population and the sample.
18
9.375
25,708
In the rhombus \(ABCD\), point \(Q\) divides side \(BC\) in the ratio \(1:3\) starting from vertex \(B\), and point \(E\) is the midpoint of side \(AB\). It is known that the median \(CF\) of triangle \(CEQ\) is equal to \(2\sqrt{2}\), and \(EQ = \sqrt{2}\). Find the radius of the circle inscribed in rhombus \(ABCD\).
\frac{\sqrt{7}}{2}
0
25,709
In $\triangle ABC$, the sides opposite to the three internal angles are $a$, $b$, and $c$, respectively. Given that $\cos A= \frac{ \sqrt {10}}{10}$ and $a\sin A+b\sin B-c\sin C= \frac{ 2 \sqrt {5}}{5}a\sin B$. 1. Find the value of $B$; 2. If $b=10$, find the area $S$ of $\triangle ABC$.
60
37.5
25,710
In the diagram, $ABCD$ and $EFGD$ are squares each with side lengths of 5 and 3 respectively, and $H$ is the midpoint of both $BC$ and $EF$. Calculate the total area of the polygon $ABHFGD$.
25.5
9.375
25,711
Define a new operation: \( x \odot y = 18 + x - a \times y \), where \( a \) is a constant. For example: \[ 1 \odot 2 = 18 + 1 - a \times 2. \] If \( 2 \odot 3 = 8 \), then what is \( 3 \odot 5 \) and \( 5 \odot 3 \)?
11
95.3125
25,712
Given the system of equations for the positive numbers \(x, y, z\): $$ \left\{\begin{array}{l} x^{2}+xy+y^{2}=108 \\ y^{2}+yz+z^{2}=16 \\ z^{2}+xz+x^{2}=124 \end{array}\right. $$ Find the value of the expression \(xy + yz + xz\).
48
87.5
25,713
In triangle $ABC$, the sides opposite to angles $A$, $B$, $C$ are denoted as $a$, $b$, $c$, respectively. If the function $f(x)=\frac{1}{3} x^{3}+bx^{2}+(a^{2}+c^{2}-ac)x+1$ has no extreme points, then the maximum value of angle $B$ is \_\_\_\_\_
\frac{\pi}{3}
67.1875
25,714
Two particles move along the edges of a square $ABCD$ with \[A \Rightarrow B \Rightarrow C \Rightarrow D \Rightarrow A,\] starting simultaneously and moving at the same speed. One starts at vertex $A$, and the other starts at the midpoint of side $CD$. The midpoint of the line segment joining the two particles traces out a path that encloses a region $R$. What is the ratio of the area of $R$ to the area of square $ABCD$? A) $\frac{1}{16}$ B) $\frac{1}{12}$ C) $\frac{1}{9}$ D) $\frac{1}{6}$ E) $\frac{1}{4}$
\frac{1}{4}
79.6875
25,715
In triangle \(ABC\), angle \(C\) equals \(30^\circ\), and angle \(A\) is acute. A line perpendicular to side \(BC\) is drawn, cutting off triangle \(CNM\) from triangle \(ABC\) (point \(N\) lies between vertices \(B\) and \(C\)). The areas of triangles \(CNM\) and \(ABC\) are in the ratio \(3:16\). Segment \(MN\) is half the height \(BH\) of triangle \(ABC\). Find the ratio \(AH:HC\).
1/3
0
25,716
Vasya wrote consecutive natural numbers \( N \), \( N+1 \), \( N+2 \), and \( N+3 \) in rectangles. Under each rectangle, he wrote the sum of the digits of the corresponding number in a circle. The sum of the numbers in the first two circles turned out to be 200, and the sum of the numbers in the third and fourth circles turned out to be 105. What is the sum of the numbers in the second and third circles?
103
1.5625
25,717
Given $f(x) = -4x^2 + 4ax - 4a - a^2$ has a maximum value of $-5$ in the interval $[0, 1]$, find the value of $a$.
-5
3.90625
25,718
In a regular tetrahedron \( P-ABCD \), where each face is an equilateral triangle with side length 1, points \( M \) and \( N \) are the midpoints of edges \( AB \) and \( BC \), respectively. Find the distance between the skew lines \( MN \) and \( PC \).
\frac{\sqrt{2}}{4}
15.625
25,719
Find the inclination angle of the line $\sqrt {2}x+ \sqrt {6}y+1=0$.
\frac{5\pi}{6}
61.71875
25,720
Let $a$ and $b$ be positive real numbers such that $a + 3b = 2.$ Find the minimum value of \[\frac{2}{a} + \frac{4}{b}.\]
14
0.78125
25,721
Given that $AC$ and $CE$ are two diagonals of a regular hexagon $ABCDEF$, and points $M$ and $N$ divide $AC$ and $CE$ internally such that $\frac{AM}{AC}=\frac{CN}{CE}=r$. If points $B$, $M$, and $N$ are collinear, find the value of $r$.
\frac{1}{\sqrt{3}}
0
25,722
How many lattice points lie on the hyperbola \( x^2 - y^2 = 1800^2 \)?
150
1.5625
25,723
Given a biased coin with probabilities of $\frac{3}{4}$ for heads and $\frac{1}{4}$ for tails, and outcomes of tosses being independent, calculate the probabilities of winning Game A and Game B.
\frac{1}{4}
1.5625
25,724
Given \(\omega = -\frac{1}{2} + \frac{1}{2}i\sqrt{3}\), representing a cube root of unity, specifically \(\omega = e^{2\pi i / 3}\). Let \(T\) denote all points in the complex plane of the form \(a + b\omega + c\omega^2\), where \(0 \leq a \leq 2\), \(0 \leq b \leq 1\), and \(0 \leq c \leq 1\). Determine the area of \(T\).
2\sqrt{3}
17.1875
25,725
29 boys and 15 girls attended a ball. Some boys danced with some girls (no more than once with each partner). After the ball, each person told their parents how many times they danced. What is the maximum number of different numbers the children could have mentioned?
29
5.46875
25,726
A cube has six faces, and each face has two diagonals. From these diagonals, choose two to form a pair. Among these pairs, how many form an angle of $60^\circ$?
48
1.5625
25,727
Given that there is a geometric sequence $\{a_n\}$ with a common ratio $q > 1$ and the sum of the first $n$ terms is $S_n$, $S_3 = 7$, the sequence $a_1+3$, $3a_2$, $a_3+4$ forms an arithmetic sequence. The sum of the first $n$ terms of the sequence $\{b_n\}$ is $T_n$, and $6T_n = (3n+1)b_n + 2$ for $n \in \mathbb{N}^*$. (1) Find the general term formula for the sequence $\{a_n\}$. (2) Find the general term formula for the sequence $\{b_n\}$. (3) Let $A = \{a_1, a_2, \ldots, a_{10}\}$, $B = \{b_1, b_2, \ldots, b_{40}\}$, and $C = A \cup B$. Calculate the sum of all elements in the set $C$.
3318
2.34375
25,728
The equations $x^3 + Cx + 20 = 0$ and $x^3 + Dx^2 + 100 = 0$ have two roots in common. Then the product of these common roots can be expressed in the form $a \sqrt[b]{c},$ where $a,$ $b,$ and $c$ are positive integers, when simplified. Find $a + b + c.$
15
19.53125
25,729
In an infinite increasing sequence of natural numbers, each number is divisible by at least one of the numbers 1005 and 1006, but none is divisible by 97. Additionally, any two consecutive numbers differ by no more than $k$. What is the smallest possible $k$ for this scenario?
2011
0.78125
25,730
Given an ellipse $\frac{x^{2}}{a^{2}} + \frac{y^{2}}{b^{2}} = 1 (a > b > 0)$ with an eccentricity $e = \frac{\sqrt{3}}{3}$. The left and right foci are $F_1$ and $F_2$, respectively, with $F_2$ coinciding with the focus of the parabola $y^2 = 4x$. (I) Find the standard equation of the ellipse; (II) If a line passing through $F_1$ intersects the ellipse at points $B$ and $D$, and another line passing through $F_2$ intersects the ellipse at points $A$ and $C$, with $AC \perp BD$, find the minimum value of $|AC| + |BD|$.
\frac{16\sqrt{3}}{5}
1.5625
25,731
Let $\mathcal{T}$ be the set of real numbers that can be represented as repeating decimals of the form $0.\overline{abcd}$ where $a, b, c, d$ are distinct digits. Find the sum of the elements of $\mathcal{T}.$
227.052227052227
0
25,732
In triangle $XYZ$, points $X'$, $Y'$, and $Z'$ are located on sides $YZ$, $XZ$, and $XY$, respectively. The cevians $XX'$, $YY'$, and $ZZ'$ are concurrent at point $P$. Given that $\frac{XP}{PX'}+\frac{YP}{PY'}+\frac{ZP}{PZ'}=100$, find the value of $\frac{XP}{PX'} \cdot \frac{YP}{PY'} \cdot \frac{ZP}{PZ'}$.
98
3.90625
25,733
In the isosceles triangle \(ABC\) with the sides \(AB = BC\), the angle \(\angle ABC\) is \(80^\circ\). Inside the triangle, a point \(O\) is taken such that \(\angle OAC = 10^\circ\) and \(\angle OCA = 30^\circ\). Find the angle \(\angle AOB\).
70
38.28125
25,734
An equilateral pentagon $AMNPQ$ is inscribed in triangle $ABC$ such that $M\in\overline{AB}$ , $Q\in\overline{AC}$ , and $N,P\in\overline{BC}$ . Suppose that $ABC$ is an equilateral triangle of side length $2$ , and that $AMNPQ$ has a line of symmetry perpendicular to $BC$ . Then the area of $AMNPQ$ is $n-p\sqrt{q}$ , where $n, p, q$ are positive integers and $q$ is not divisible by the square of a prime. Compute $100n+10p+q$ . *Proposed by Michael Ren*
5073
0
25,735
The volume of the solid generated by rotating the circle $x^2 + (y + 1)^2 = 3$ around the line $y = kx - 1$ for one complete revolution is what?
4\sqrt{3}\pi
24.21875
25,736
Let the set \( I = \{1, 2, \cdots, n\} (n \geqslant 3) \). If two non-empty proper subsets \( A \) and \( B \) of \( I \) satisfy \( A \cap B = \varnothing \) and \( A \cup B = I \), then \( A \) and \( B \) are called a partition of \( I \). If for any partition \( A \) and \( B \) of the set \( I \), there exist two numbers in \( A \) or \( B \) such that their sum is a perfect square, then \( n \) must be at least \(\qquad\).
15
69.53125
25,737
Around the outside of a $6$ by $6$ square, construct four semicircles with the four sides of the square as their diameters. Another square, $EFGH$, has its sides parallel to the corresponding sides of the larger square, and each side of $EFGH$ is tangent to one of the semicircles. Provide the area of square $EFGH$. A) $36$ B) $64$ C) $100$ D) $144$ E) $256$
144
1.5625
25,738
$10 \cdot 52 \quad 1990-1980+1970-1960+\cdots-20+10$ equals:
1000
27.34375
25,739
A grid consists of multiple squares, as shown below. Count the different squares possible using the lines in the grid. [asy] unitsize(0.5 cm); int i, j; for(i = 0; i <= 5; ++i) { draw((0,i)--(5,i)); draw((i,0)--(i,5)); } for(i = 1; i <= 4; ++i) { for (j = 1; j <= 4; ++j) { if ((i > 1 && i < 4) || (j > 1 && j < 4)) continue; draw((i,j)--(i,j+1)--(i+1,j+1)--(i+1,j)--cycle); } } [/asy]
54
0.78125
25,740
A regular octagon is inscribed in a circle and another regular octagon is circumscribed about the same circle. What is the ratio of the area of the larger octagon to the area of the smaller octagon? Express your answer as a common fraction.
2 + \sqrt{2}
3.125
25,741
$ABCD$ is a regular tetrahedron. Let $N$ be the midpoint of $\overline{AB}$, and let $G$ be the centroid of triangle $ACD$. What is $\cos \angle BNG$?
\frac{1}{3}
21.09375
25,742
An artist arranges 1000 dots evenly around a circle, with each dot being either red or blue. A critic counts faults: each pair of adjacent red dots counts as one fault, and each pair of blue dots exactly two apart (separated by one dot) counts as another fault. What is the smallest number of faults the critic could find?
250
3.125
25,743
Given that in triangle $\triangle ABC$, the sides opposite to angles $A$, $B$, and $C$ are $a$, $b$, and $c$ respectively, and $\sqrt{3}a\cos C=c\sin A$. $(1)$ Find the measure of angle $C$. $(2)$ If $a > 2$ and $b-c=1$, find the minimum perimeter of triangle $\triangle ABC$.
9 + 6\sqrt{2}
0
25,744
For a natural number $b$ , let $N(b)$ denote the number of natural numbers $a$ for which the equation $x^2 + ax + b = 0$ has integer roots. What is the smallest value of $b$ for which $N(b) = 20$ ?
240
74.21875
25,745
Starting at $(0,0),$ an object moves in the coordinate plane via a sequence of steps, each of length one. Each step is to the left, right, up, or down, all four equally likely. Let $q$ be the probability that the object reaches $(3,3)$ in eight or fewer steps. Write $q$ in the form $a/b$, where $a$ and $b$ are relatively prime positive integers. Find $a+b.$
4151
1.5625
25,746
Given the product \( S = \left(1+2^{-\frac{1}{32}}\right)\left(1+2^{-\frac{1}{16}}\right)\left(1+2^{-\frac{1}{8}}\right)\left(1+2^{-\frac{1}{4}}\right)\left(1+2^{-\frac{1}{2}}\right) \), calculate the value of \( S \).
\frac{1}{2}\left(1 - 2^{-\frac{1}{32}}\right)^{-1}
0
25,747
A capacitor with a capacitance of $C_{1} = 20 \mu$F is charged to a voltage $U_{1} = 20$ V. A second capacitor with a capacitance of $C_{2} = 5 \mu$F is charged to a voltage $U_{2} = 5$ V. The capacitors are connected with opposite-charged plates. Determine the voltage that will be established across the plates.
15
48.4375
25,748
Let \( x \) and \( y \) be non-zero real numbers such that \[ \frac{x \sin \frac{\pi}{5} + y \cos \frac{\pi}{5}}{x \cos \frac{\pi}{5} - y \sin \frac{\pi}{5}} = \tan \frac{9 \pi}{20}. \] (1) Find the value of \(\frac{y}{x}\). (2) In triangle \( \triangle ABC \), if \( \tan C = \frac{y}{x} \), find the maximum value of \( \sin 2A + 2 \cos B \).
\frac{3}{2}
0.78125
25,749
Given the function $f(x) = 2\sin^2\left(\frac{\pi}{4} + x\right) - \sqrt{3}\cos{2x} - 1$, where $x \in \mathbb{R}$: 1. If the graph of function $h(x) = f(x + t)$ is symmetric about the point $\left(-\frac{\pi}{6}, 0\right)$, and $t \in \left(0, \frac{\pi}{2}\right)$, find the value of $t$. 2. In an acute triangle $ABC$, if angle $A$ satisfies $h(A) = 1$, find the range of $(\sqrt{3} - 1)\sin{B} + \sqrt{2}\sin{C}$.
\frac{\pi}{3}
0.78125
25,750
Determine the smallest integer $n > 1$ with the property that $n^2(n - 1)$ is divisible by 2009.
42
48.4375
25,751
In a debate competition with four students participating, the rules are as follows: Each student must choose one question to answer from two given topics, Topic A and Topic B. For Topic A, answering correctly yields 100 points and answering incorrectly results in a loss of 100 points. For Topic B, answering correctly yields 90 points and answering incorrectly results in a loss of 90 points. If the total score of the four students is 0 points, how many different scoring situations are there?
36
34.375
25,752
The cells of a $50 \times 50$ table are colored in $n$ colors such that for any cell, the union of its row and column contains cells of all $n$ colors. Find the maximum possible number of blue cells if (a) $n=2$ (b) $n=25$.
1300
0.78125
25,753
How many four-digit numbers are composed of four distinct digits such that one digit is the average of any two other digits?
240
2.34375
25,754
Let \[P(x) = (3x^5 - 45x^4 + gx^3 + hx^2 + ix + j)(4x^3 - 60x^2 + kx + l),\] where $g, h, i, j, k, l$ are real numbers. Suppose that the set of all complex roots of $P(x)$ includes $\{1, 2, 3, 4, 5, 6\}$. Find $P(7)$.
51840
1.5625
25,755
A cube is inscribed in a regular octahedron in such a way that its vertices lie on the edges of the octahedron. By what factor is the surface area of the octahedron greater than the surface area of the inscribed cube?
\frac{2\sqrt{3}}{3}
38.28125
25,756
Given that $F_1$ and $F_2$ are the left and right foci of the hyperbola $\frac{x^2}{a^2}-\frac{y^2}{b^2}=1$ where $a>0$ and $b>0$. If the point $F_2$ is symmetric with respect to the asymptote line and lies on the hyperbola, calculate the eccentricity of the hyperbola.
\sqrt{5}
43.75
25,757
For all positive integers $m>10^{2022}$ , determine the maximum number of real solutions $x>0$ of the equation $mx=\lfloor x^{11/10}\rfloor$ .
10
6.25
25,758
Multiply the first eight positive composite integers, add the first prime number to this product, then divide by the product of the next eight positive composite integers after adding the second prime number to it. Express your answer as a common fraction.
\frac{4 \cdot 6 \cdot 8 \cdot 9 \cdot 10 \cdot 12 \cdot 14 \cdot 15 + 2}{16 \cdot 18 \cdot 20 \cdot 21 \cdot 22 \cdot 24 \cdot 25 \cdot 26 + 3}
0
25,759
Given \(\triangle DEF\), where \(DE=28\), \(EF=30\), and \(FD=16\), calculate the area of \(\triangle DEF\).
221.25
0
25,760
From the numbers 0, 1, 2, 3, 4, select three different digits to form a three-digit number. What is the sum of the units digit of all these three-digit numbers?
90
85.15625
25,761
The numbers \(1000^{2}, 1001^{2}, 1002^{2}, \ldots\) have their last three digits discarded. How many of the first terms in the resulting sequence form an arithmetic progression?
32
3.125
25,762
Compute $\tan\left(\frac{\pi}{9}\right)\tan\left(\frac{2\pi}{9}\right)\tan\left(\frac{4\pi}{9}\right)$.
\frac{1}{3}
0
25,763
How many values of $x$, $-10 < x < 50$, satisfy $\cos^2 x + 3\sin^2 x = 1.5?$ (Note: $x$ is measured in radians.)
18
0.78125
25,764
Remove five out of twelve digits so that the remaining numbers sum up to 1111. $$ \begin{array}{r} 111 \\ 333 \\ +\quad 777 \\ 999 \\ \hline 1111 \end{array} $$
1111
7.03125
25,765
Add together the numbers $7.56$ and $4.29$. Write the result as a decimal.
11.85
94.53125
25,766
Among the following propositions, the correct ones are __________. (1) The regression line $\hat{y}=\hat{b}x+\hat{a}$ always passes through the center of the sample points $(\bar{x}, \bar{y})$, and at least through one sample point; (2) After adding the same constant to each data point in a set of data, the variance remains unchanged; (3) The correlation index $R^{2}$ is used to describe the regression effect; it represents the contribution rate of the forecast variable to the change in the explanatory variable, the closer to $1$, the better the model fits; (4) If the observed value $K$ of the random variable $K^{2}$ for categorical variables $X$ and $Y$ is larger, then the credibility of "$X$ is related to $Y$" is smaller; (5) For the independent variable $x$ and the dependent variable $y$, when the value of $x$ is certain, the value of $y$ has certain randomness, the non-deterministic relationship between $x$ and $y$ is called a function relationship; (6) In the residual plot, if the residual points are relatively evenly distributed in a horizontal band area, it indicates that the chosen model is relatively appropriate; (7) Among two models, the one with the smaller sum of squared residuals has a better fitting effect.
(2)(6)(7)
0
25,767
Given a sequence $\{a_{n}\}$ where $a_{1}=1$ and $a_{n+1}-a_{n}=\left(-1\right)^{n+1}\frac{1}{n(n+2)}$, calculate the sum of the first 40 terms of the sequence $\{\left(-1\right)^{n}a_{n}\}$.
\frac{20}{41}
1.5625
25,768
What is the least integer whose square is 75 more than its double?
-8
17.96875
25,769
Given that $| \vec{e} | = 1$ and it satisfies $| \vec{a} + \vec{e} | = | \vec{a} - 2\vec{e} |$, find the projection of vector $\vec{a}$ in the direction of $\vec{e}$.
\frac{1}{2}
22.65625
25,770
What is $\frac{1}{(-5^2)^3} \cdot (-5)^8 \cdot \sqrt{5}$?
5^{5/2}
0
25,771
Two students, A and B, are playing table tennis. They have agreed on the following rules: ① Each point won earns 1 point; ② They use a three-point serve system, meaning they switch serving every three points. Assuming that when A serves, the probability of A winning a point is $\frac{3}{5}$, and when B serves, the probability of A winning a point is $\frac{1}{2}$, and the outcomes of each point are independent. According to the draw result, A serves first. $(1)$ Let $X$ represent the score of A after three points. Find the distribution table and mean of $X$; $(2)$ Find the probability that A has more points than B after six points.
\frac{441}{1000}
0.78125
25,772
Given that spinner A contains the numbers 4, 5, 6, spinner B contains the numbers 1, 2, 3, 4, 5, and spinner C can take numbers from the set 7, 8, 9 if spinner B lands on an odd number and the set {6, 8} if spinner B lands on an even number, find the probability that the sum of the numbers resulting from the rotation of spinners A, B, and C is an odd number.
\frac{4}{15}
4.6875
25,773
Find the number of integers $n$ with $1\le n\le 100$ for which $n-\phi(n)$ is prime. Here $\phi(n)$ denotes the number of positive integers less than $n$ which are relatively prime to $n$ . *Proposed by Mehtaab Sawhney*
13
0.78125
25,774
Given that the decomposition rate $v$ of a certain type of garbage approximately satisfies the relationship $v=a\cdot b^{t}$, where $a$ and $b$ are positive constants, and the decomposition rate is $5\%$ after $6$ months and $10\%$ after $12$ months, calculate the time it takes for this type of garbage to completely decompose.
32
1.5625
25,775
Each of 100 students sends messages to 50 different students. What is the least number of pairs of students who send messages to each other?
50
10.15625
25,776
8 people are sitting around a circular table for a meeting, including one leader, one vice leader, and one recorder. If the recorder is seated between the leader and vice leader, how many different seating arrangements are possible (considering that arrangements that can be obtained by rotation are identical)?
240
55.46875
25,777
Rectangle PQRS and right triangle SRT share side SR and have the same area. Rectangle PQRS has dimensions PQ = 4 and PS = 8. Find the length of side RT.
16
10.9375
25,778
10 times 0.1 equals to ____, 10 times 0.01 equals to ____, 10 times 0.001 equals to ____.
0.01
11.71875
25,779
In the sequence $\{a_n\}$, $a_1 = 1$, $a_2 = 2$, $a_{n+2}$ is equal to the remainder of $a_n + a_{n+1}$ divided by 3. Find the sum of the first 89 terms of $\{a_n\}$.
100
19.53125
25,780
Find the smallest positive integer $k$ such that $1^2 + 2^2 + 3^2 + \ldots + k^2$ is a multiple of $360$.
175
0
25,781
From the natural numbers 1 to 2008, the maximum number of numbers that can be selected such that the sum of any two selected numbers is not divisible by 3 is ____.
671
36.71875
25,782
A graph has 1982 points. Given any four points, there is at least one joined to the other three. What is the smallest number of points which are joined to 1981 points?
1979
0.78125
25,783
Find the positive integer $N$, such that numbers $N$ and $N^2$ end in the same sequence of four digits $abcd$ where $a$ is not zero, under the modulus $8000$.
625
0
25,784
Given the function $f\left(x\right)=x^{2}-2bx+3$, where $b\in R$. $(1)$ Find the solution set of the inequality $f\left(x\right) \lt 4-b^{2}$. $(2)$ When $x\in \left[-1,2\right]$, the function $y=f\left(x\right)$ has a minimum value of $1$. Find the maximum value of the function $y=f\left(x\right)$ when $x\in \left[-1,2\right]$.
4 + 2\sqrt{2}
15.625
25,785
Each vertex of a convex hexagon $ABCDEF$ is to be assigned a color. There are $7$ colors to choose from, and no two adjacent vertices can have the same color, nor can the vertices at the ends of each diagonal. Calculate the total number of different colorings possible.
5040
0
25,786
Find the value of $k$ for the ellipse $\frac{x^2}{k+8} + \frac{y^2}{9} = 1$ with an eccentricity of $\frac{1}{2}$.
-\frac{5}{4}
13.28125
25,787
Pedro must choose two irreducible fractions, each with a positive numerator and denominator such that: - The sum of the fractions is equal to $2$ . - The sum of the numerators of the fractions is equal to $1000$ . In how many ways can Pedro do this?
200
8.59375
25,788
Let $U$ be a positive integer whose only digits are 0s and 1s. If $Y = U \div 18$ and $Y$ is an integer, what is the smallest possible value of $Y$?
61728395
50.78125
25,789
A right circular cone is sliced into three pieces by planes parallel to its base, each piece having equal height. The pieces are labeled from top to bottom; hence the smallest piece is at the top and the largest at the bottom. Calculate the ratio of the volume of the smallest piece to the volume of the largest piece.
\frac{1}{27}
3.125
25,790
Given a sequence $\{a\_n\}$ with its first $n$ terms sum $S\_n$, where $a\_1=1$ and $3S\_n = a_{n+1} - 1$. 1. Find the general formula for the sequence $\{a\_n\}$. 2. Consider an arithmetic sequence $\{b\_n\}$ with its first $n$ terms sum $T\_n$, where $a\_2 = b\_2$ and $T\_4 = 1 + S\_3$. Find the value of $\frac{1}{b\_1 \cdot b\_2} + \frac{1}{b\_2 \cdot b\_3} + \dots + \frac{1}{b_{10}b_{11}}$.
\frac{10}{31}
91.40625
25,791
The maximum and minimum values of the function $y=2x^{3}-3x^{2}-12x+5$ on the interval $[0,3]$ need to be determined.
-15
87.5
25,792
In triangle \(ABC\), point \(O\) is the center of the circumcircle, and point \(L\) is the midpoint of side \(AB\). The circumcircle of triangle \(ALO\) intersects the line \(AC\) at point \(K\). Find the area of triangle \(ABC\) if \(\angle LOA = 45^\circ\), \(LK = 8\), and \(AK = 7\).
112
0
25,793
The sides of triangle $DEF$ are in the ratio of $3:4:5$. Segment $EG$ is the angle bisector drawn to the shortest side, dividing it into segments $DG$ and $GE$. What is the length, in inches, of the longer subsegment of side $DE$ if the length of side $DE$ is $12$ inches? Express your answer as a common fraction.
\frac{48}{7}
3.125
25,794
On a table, there are 20 cards numbered from 1 to 20. Each time, Xiao Ming picks out 2 cards such that the number on one card is 2 more than twice the number on the other card. What is the maximum number of cards Xiao Ming can pick?
12
13.28125
25,795
Let $(a_1,a_2,\ldots, a_{13})$ be a permutation of $(1, 2, \ldots, 13)$ . Ayvak takes this permutation and makes a series of *moves*, each of which consists of choosing an integer $i$ from $1$ to $12$ , inclusive, and swapping the positions of $a_i$ and $a_{i+1}$ . Define the *weight* of a permutation to be the minimum number of moves Ayvak needs to turn it into $(1, 2, \ldots, 13)$ . The arithmetic mean of the weights of all permutations $(a_1, \ldots, a_{13})$ of $(1, 2, \ldots, 13)$ for which $a_5 = 9$ is $\frac{m}{n}$ , for coprime positive integers $m$ and $n$ . Find $100m+n$ . *Proposed by Alex Gu*
13703
0
25,796
Points $A=(8,15)$ and $B=(14,9)$ lie on circle $\omega$ in the plane. Suppose the tangent lines to $\omega$ at $A$ and $B$ intersect at a point on the x-axis. Find the area of $\omega$.
306\pi
3.125
25,797
A box contains 4 labels marked with the numbers $1$, $2$, $3$, and $4$. Two labels are randomly selected according to the following conditions. Find the probability that the numbers on the two labels are consecutive integers: 1. The selection is made without replacement; 2. The selection is made with replacement.
\frac{3}{16}
0.78125
25,798
Compute \[\sin^2 6^\circ + \sin^2 12^\circ + \sin^2 18^\circ + \dots + \sin^2 174^\circ.\]
15
16.40625
25,799
Calculate $1010101_2 + 110011_2$ and express your answer in base $10$.
136
57.8125