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Find the smallest natural number ending with the digit 2, which doubles if this digit is moved to the beginning.
105263157894736842
0
8,192
-1
8,192
1. Convert the parametric equations of the conic curve $C$: $$ \begin{cases} x=t^{2}+ \frac {1}{t^{2}}-2 \\ y=t- \frac {1}{t} \end{cases} $$ ($t$ is the parameter) into a Cartesian coordinate equation. 2. If the polar equations of two curves are $\rho=1$ and $\rho=2\cos\left(\theta+ \frac {\pi}{3}\right)$ respectiv...
\sqrt {3}
0
4,058.25
-1
4,058.25
A sequence $y_1,y_2,\dots,y_k$ of real numbers is called \emph{zigzag} if $k=1$, or if $y_2-y_1, y_3-y_2, \dots, y_k-y_{k-1}$ are nonzero and alternate in sign. Let $X_1,X_2,\dots,X_n$ be chosen independently from the uniform distribution on $[0,1]$. Let $a(X_1,X_2,\dots,X_n)$ be the largest value of $k$ for which ther...
\frac{2n+2}{3}
The expected value is $\frac{2n+2}{3}$. Divide the sequence $X_1,\dots,X_n$ into alternating increasing and decreasing segments, with $N$ segments in all. Note that removing one term cannot increase $N$: if the removed term is interior to some segment then the number remains unchanged, whereas if it separates two segme...
0
8,192
-1
8,192
Bob knows that Alice has 2021 secret positive integers $x_{1}, \ldots, x_{2021}$ that are pairwise relatively prime. Bob would like to figure out Alice's integers. He is allowed to choose a set $S \subseteq\{1,2, \ldots, 2021\}$ and ask her for the product of $x_{i}$ over $i \in S$. Alice must answer each of Bob's quer...
11
In general, Bob can find the values of all $n$ integers asking only $\left\lfloor\log _{2} n\right\rfloor+1$ queries. For each of Alice's numbers $x_{i}$, let $Q_{i}$ be the set of queries $S$ such that $i \in S$. Notice that all $Q_{i}$ must be nonempty and distinct. If there exists an empty $Q_{i}$, Bob has asked no ...
0.1875
8,074.9375
7,567.666667
8,192
$30$ same balls are put into four boxes $A$, $B$, $C$, $D$ in such a way that sum of number of balls in $A$ and $B$ is greater than sum of in $C$ and $D$. How many possible ways are there?
2600
0.375
7,432.75
6,167.333333
8,192
If $\tan(\alpha-\beta) = \frac{1}{2}$ and $\tan(\alpha+\beta) = \frac{1}{3}$, calculate the value of $\tan 2\beta$.
- \frac{1}{7}
0.875
5,104.3125
4,663.214286
8,192
Two places, A and B, are 12 km apart. Cars A and B depart from place A towards place B one after the other at a constant speed. Car A takes 15 minutes to travel from A to B, while Car B takes 10 minutes. If Car B departs 2 minutes later than Car A: 1. Write the functions representing the distance traveled by Cars A and...
7.2
0.0625
5,995
8,192
5,848.533333
Suppose $\triangle ABC$ is a triangle where $AB = 36, AC = 36$, and $\angle B = 60^\circ$. A point $P$ is considered a fold point if the creases formed when vertices $A, B,$ and $C$ are folded onto point $P$ do not intersect inside $\triangle ABC$. Find the area of the set of all fold points of $\triangle ABC$, given i...
381
0
8,146.1875
-1
8,146.1875
Given functions $f(x)$ and $g(x)$, where the graph of $g(x)$ is symmetric about $x=1$, and $f(x) - g(x) = 1$, $f(x+1) + g(2-x) = 1$, and $g(1) = 3$, find $\sum_{i=1}^{23}f(x)=$____.
26
0.6875
4,953.375
3,854.818182
7,370.2
Given the sequence \(\left\{a_{n}\right\}\) that satisfies \[ a_{n}=\left[(2+\sqrt{5})^{n}+\frac{1}{2^{n}}\right] \quad \text{for} \quad n \in \mathbf{Z}_{+}, \] where \([x]\) denotes the greatest integer less than or equal to the real number \(x\). Let \(C\) be a real number such that for any positive integer \(n\), \...
\frac{\sqrt{5} - 2}{4}
0
8,192
-1
8,192
If $(x + 2)(3x^2 - x + 5) = Ax^3 + Bx^2 + Cx + D$, what is the value of $A + B + C + D$?
21
1
1,782.875
1,782.875
-1
What is the least common multiple of 105 and 360?
2520
1
3,125.375
3,125.375
-1
A rectangular prism has 4 green faces, 2 yellow faces, and 6 blue faces. What's the probability that when it is rolled, a blue face will be facing up?
\frac{1}{2}
0.6875
5,296.6875
3,980.636364
8,192
Simplify $2a(2a^2 + a) - a^2$.
4a^3 + a^2
1
1,567.3125
1,567.3125
-1
In triangle $ABC$ , $AB=13$ , $BC=14$ and $CA=15$ . Segment $BC$ is split into $n+1$ congruent segments by $n$ points. Among these points are the feet of the altitude, median, and angle bisector from $A$ . Find the smallest possible value of $n$ . *Proposed by Evan Chen*
27
0.625
7,155.9375
6,534.3
8,192
The line $y = \frac{3}{2} x - 25$ is parameterized by $(x,y) = (f(t),15t - 7).$ Enter the function $f(t).$
10t + 12
1
2,176.375
2,176.375
-1
Given that \(ABCD-A_{1}B_{1}C_{1}D_{1}\) is a cube and \(P-A_{1}B_{1}C_{1}D_{1}\) is a regular tetrahedron, find the cosine of the angle between the skew lines \(A_{1}P\) and \(BC_{1}\), given that the distance from point \(P\) to plane \(ABC\) is \(\frac{3}{2}AB\).
\frac{\sqrt{6}}{3}
0
7,663.125
-1
7,663.125
Given the acute angle \( x \) that satisfies the equation \( \sin^3 x + \cos^3 x = \frac{\sqrt{2}}{2} \), find \( x \).
\frac{\pi}{4}
0.6875
5,883.25
4,833.818182
8,192
Let $M$ be the greatest integer multiple of 9, no two of whose digits are the same. What is the remainder when $M$ is divided by 1000?
963
0
3,997.625
-1
3,997.625
The sum of the first thirteen terms of an arithmetic progression is $50\%$ of the sum of the last thirteen terms of this progression. The sum of all terms of this progression, excluding the first three terms, is to the sum of all terms excluding the last three terms in the ratio $5:4$. Find the number of terms in this ...
22
0.1875
7,857.125
6,406
8,192
Determine all integers $ n > 1$ such that \[ \frac {2^n \plus{} 1}{n^2} \] is an integer.
n=\boxed {1,3}
Let us consider the problem of finding all integers \( n > 1 \) such that the expression \[ \frac{2^n + 1}{n^2} \] is an integer. We need to identify those values of \( n \) for which \( n^2 \mid (2^n + 1) \). First, let us examine small values of \( n \): 1. For \( n = 2 \): \[ 2^2 + 1 = 4 + 1 = 5 \quad \t...
0
8,192
-1
8,192
$a,b,c$ are positive numbers such that $ a^2 + b^2 + c^2 = 2abc + 1 $ . Find the maximum value of \[ (a-2bc)(b-2ca)(c-2ab) \]
1/8
0.0625
8,162.9375
7,727
8,192
A line \( l \) passes through the focus \( F \) of the parabola \( y^2 = 4x \) and intersects the parabola at points \( A \) and \( B \). Point \( M \) is given as \( (4,0) \). Extending \( AM \) and \( BM \) intersects the parabola again at points \( C \) and \( D \), respectively. Find the value of \(\frac{S_{\triang...
16
0
8,192
-1
8,192
For every real number $x$, let $\lfloor x\rfloor$ denote the greatest integer not exceeding $x$, and let $f(x) = \lfloor x\rfloor(2014^{x-\lfloor x\rfloor}-1)$. The set of all numbers $x$ such that $1\leq x<2014$ and $f(x)\leq 1$ is a union of disjoint intervals. What is the sum of the lengths of those intervals?
1
1. **Define the function and interval**: Given the function \( f(x) = \lfloor x \rfloor (2014^{x - \lfloor x \rfloor} - 1) \), we need to find the set of \( x \) such that \( 1 \leq x < 2014 \) and \( f(x) \leq 1 \). 2. **Simplify the function**: Let \( \lfloor x \rfloor = k \), where \( k \) is an integer and \( 1 \l...
0.8125
4,723.875
3,923.538462
8,192
Carrie has a rectangular garden that measures $6$ feet by $8$ feet. She plants the entire garden with strawberry plants. Carrie is able to plant $4$ strawberry plants per square foot, and she harvests an average of $10$ strawberries per plant. How many strawberries can she expect to harvest?
1920
1. **Calculate the area of the garden**: The garden is a rectangle with dimensions $6$ feet by $8$ feet. The area \( A \) of a rectangle is given by the formula: \[ A = \text{length} \times \text{width} \] Substituting the given dimensions: \[ A = 6 \text{ ft} \times 8 \text{ ft} = 48 \text{ ft}^...
0.9375
1,764.125
1,335.6
8,192
Bonnie constructs a frame for a cube using 12 pieces of wire that are each eight inches long. Meanwhile, Roark uses 2-inch-long pieces of wire to create a collection of unit cube frames that are not connected. The total volume of Roark's cubes is the same as the volume of Bonnie’s cube. What is the ratio of the total l...
\frac{1}{128}
0.3125
3,133.6875
2,036
3,632.636364
If $y=x+\frac{1}{x}$, then $x^4+x^3-4x^2+x+1=0$ becomes:
$x^2(y^2+y-6)=0$
1. **Express $y$ in terms of $x$:** Given $y = x + \frac{1}{x}$. 2. **Square $y$ to find $y^2$:** \[ y^2 = \left(x + \frac{1}{x}\right)^2 = x^2 + 2 + \frac{1}{x^2} \] 3. **Express $x^2 y^2$ in terms of $x$:** \[ x^2 y^2 = x^2 \left(x^2 + 2 + \frac{1}{x^2}\right) = x^4 + 2x^2 + 1 \] 4. **Express ...
0
5,294.75
-1
5,294.75
Compute the prime factorization of 1007021035035021007001.
7^{7} \cdot 11^{7} \cdot 13^{7}
The number in question is $$\sum_{i=0}^{7}\binom{7}{i} 1000^{i}=(1000+1)^{7}=1001^{7}=7^{7} \cdot 11^{7} \cdot 13^{7}$$
0
7,917.5625
-1
7,917.5625
In $\triangle ABC$, the sides opposite to angles A, B, and C are $a$, $b$, and $c$, respectively. Given the equation $$2b\cos A - \sqrt{3}c\cos A = \sqrt{3}a\cos C$$. (1) Find the value of angle A; (2) If $\angle B = \frac{\pi}{6}$, and the median $AM = \sqrt{7}$ on side $BC$, find the area of $\triangle ABC$.
\sqrt{3}
0.5625
6,900.3125
5,895.666667
8,192
In $\triangle ABC$, the median from vertex $A$ is perpendicular to the median from vertex $B$. The lengths of sides $AC$ and $BC$ are 6 and 7 respectively. Calculate the length of side $AB$.
\sqrt{17}
0.8125
5,752.5625
5,189.615385
8,192
The function $f(x)$ satisfies \[f(x - y) = f(x) f(y)\]for all real numbers $x$ and $y,$ and $f(x) \neq 0$ for all real numbers $x.$ Find $f(3).$
1
1
4,240.125
4,240.125
-1
Determine the value of the following sum: $$ \log _{3}\left(1-\frac{1}{15}\right)+\log _{3}\left(1-\frac{1}{14}\right)+\log _{3}\left(1-\frac{1}{13}\right)+\cdots+\log _{3}\left(1-\frac{1}{8}\right)+\log _{3}\left(1-\frac{1}{7}\right)+\log _{3}\left(1-\frac{1}{6}\right) $$ (Note that the sum includes a total of 10 te...
-1
0.6875
3,781.375
2,308
7,022.8
Beatrix is going to place six rooks on a $6 \times 6$ chessboard where both the rows and columns are labeled $1$ to $6$; the rooks are placed so that no two rooks are in the same row or the same column. The $value$ of a square is the sum of its row number and column number. The $score$ of an arrangement of rooks is the...
371
So we first count the number of permutations with score $\ge 2$. This is obviously $6!=720$. Then, the number of permutations with score $\ge 3$ can also be computed: in the first column, there are five ways to place a rook- anywhere but the place with score $1$. In the next column, there are $5$ ways to place a rook- ...
0
8,192
-1
8,192
Let $M$ denote the number of positive integers which divide 2014!, and let $N$ be the integer closest to $\ln (M)$. Estimate the value of $N$. If your answer is a positive integer $A$, your score on this problem will be the larger of 0 and $\left\lfloor 20-\frac{1}{8}|A-N|\right\rfloor$. Otherwise, your score will be z...
439
Combining Legendre's Formula and the standard prime approximations, the answer is $$\prod_{p}\left(1+\frac{2014-s_{p}(2014)}{p-1}\right)$$ where $s_{p}(n)$ denotes the sum of the base $p$-digits of $n$. Estimate $\ln 1000 \approx 8$, and $\ln 2014 \approx 9$. Using the Prime Number Theorem or otherwise, one might estim...
0
8,192
-1
8,192
Given \( \frac{1}{3} \leqslant a \leqslant 1 \), if \( f(x)=a x^{2}-2 x+1 \) attains its maximum value \( M(a) \) and minimum value \( N(a) \) on the interval \([1,3]\), and let \( g(a)=M(a)-N(a) \), then the minimum value of \( g(a) \) is \(\quad\) .
\frac{1}{2}
0.375
7,390.8125
6,616.5
7,855.4
Each positive integer number $n \ ge 1$ is assigned the number $p_n$ which is the product of all its non-zero digits. For example, $p_6 = 6$ , $p_ {32} = 6$ , $p_ {203} = 6$ . Let $S = p_1 + p_2 + p_3 + \dots + p_ {999}$ . Find the largest prime that divides $S $ .
103
0.375
5,982.9375
4,361.833333
6,955.6
Using only the paths and the directions shown, how many different routes are there from $\text{M}$ to $\text{N}$?
6
To solve this problem, we will use a systematic approach by counting the number of ways to reach $\text{N}$ from each point, starting from the points closest to $\text{N}$ and working backwards. 1. **From $\text{C}$ to $\text{N}$**: There is only one direct path from $\text{C}$ to $\text{N}$, which is $\text{CN}$. Thu...
0.375
5,494.125
4,290.833333
6,216.1
For each integer from 1 through 2019, Tala calculated the product of its digits. Compute the sum of all 2019 of Tala's products.
184320
0.3125
7,869.625
7,408.8
8,079.090909
A sphere with center $O$ has radius $6$. A triangle with sides of length $15, 15,$ and $24$ is situated in space so that each of its sides is tangent to the sphere. What is the distance between $O$ and the plane determined by the triangle?
$2\sqrt{5}$
1. **Understanding the Problem**: A sphere with radius $6$ is tangent to all sides of a triangle with sides $15, 15, 24$. We need to find the distance from the center of the sphere, $O$, to the plane of the triangle. 2. **Triangle's Inradius**: The triangle's sides are tangent to the sphere, implying that the sphere's...
0
4,437
-1
4,437
At what point does the line containing the points $(1, 7)$ and $(3, 11)$ intersect the $y$-axis? Express your answer as an ordered pair.
(0,5)
1
1,494.5625
1,494.5625
-1
An equilateral triangle of side length $10$ is completely filled in by non-overlapping equilateral triangles of side length $1$. How many small triangles are required?
100
To solve this problem, we need to determine how many small equilateral triangles of side length $1$ can fit into a larger equilateral triangle of side length $10$. #### Method 1: Summing the Number of Triangles in Each Row 1. **Visualize the Triangle**: Imagine the large triangle divided into rows of smaller equilater...
0.9375
5,720.9375
5,556.2
8,192
Consider all possible broken lines that travel along the sides of the cells and connect two opposite corners of a square sheet of grid paper with dimensions $100 \times 100$ by the shortest path. What is the minimum number of such broken lines that need to be taken so that their union contains all the vertices of the c...
101
0
8,095.375
-1
8,095.375
A book with 53 pages numbered 1 to 53 has its pages renumbered in reverse, from 53 to 1. For how many pages do the new page number and old page number share the same units digit?
11
0.5625
5,928.625
4,954.444444
7,181.142857
A circle inscribed in triangle \( ABC \) touches side \( AB \) at point \( M \), and \( AM = 1 \), \( BM = 4 \). Find \( CM \) given that \( \angle BAC = 120^\circ \).
\sqrt{273}
0.3125
7,039.0625
6,606.6
7,235.636364
A sequence of integers $a_1, a_2, a_3, \ldots$ is chosen so that $a_n = a_{n - 1} - a_{n - 2}$ for each $n \ge 3$. What is the sum of the first 2001 terms of this sequence if the sum of the first 1492 terms is 1985, and the sum of the first 1985 terms is 1492?
986
The problem gives us a sequence defined by a recursion, so let's calculate a few values to get a feel for how it acts. We aren't given initial values, so let $a_1 = a$ and $a_2 = b$. Then $a_3 = b - a$, $a_4 = (b - a) - b = -a$, $a_5 = -a - (b - a) = -b$, $a_6 = -b - (-a) = a - b$, $a_7 = (a - b) - (-b) = a$ and $a_8 =...
0.9375
4,579.625
4,338.8
8,192
Let $\triangle A B C$ be a triangle inscribed in a unit circle with center $O$. Let $I$ be the incenter of $\triangle A B C$, and let $D$ be the intersection of $B C$ and the angle bisector of $\angle B A C$. Suppose that the circumcircle of $\triangle A D O$ intersects $B C$ again at a point $E$ such that $E$ lies on ...
\frac{15}{169}
Consider the following lemma: Lemma. $A D \perp E O$. Proof. By the Shooting Lemma, the reflection of the midpoint $M$ of arc $B C$ not containing $A$ over $B C$ lies on $(A D O)$. Hence $\measuredangle A D E+\measuredangle D E O=\measuredangle M D C+\measuredangle D M^{\prime} O=\measuredangle M D C+\measuredangle M^{...
0
8,192
-1
8,192
What integer $n$ satisfies $0\le n<19$ and $$38574\equiv n\pmod{19}~?$$
4
0.875
5,517.6875
5,135.642857
8,192
Given $x \gt 0$, $y \gt 0$, when $x=$______, the maximum value of $\sqrt{xy}(1-x-2y)$ is _______.
\frac{\sqrt{2}}{16}
0
6,317.75
-1
6,317.75
Compute $(1 + i)^4.$
-4
1
2,641.125
2,641.125
-1
Find $x$ such that $\lceil x \rceil \cdot x = 156$. Express $x$ as a decimal.
12
0
8,192
-1
8,192
Given the function $f(x)=-\cos^2 x + \sqrt{3}\sin x\sin\left(x + \frac{\pi}{2}\right)$, find the sum of the minimum and maximum values of $f(x)$ when $x \in \left[0, \frac{\pi}{2}\right]$.
-\frac{1}{2}
0.9375
5,884.1875
5,730.333333
8,192
The average (mean) of two numbers is 7. One of the numbers is 5. What is the other number?
9
Since the average of two numbers is 7, their sum is $2 imes 7=14$. Since one of the numbers is 5, the other is $14-5=9$.
1
968.5625
968.5625
-1
How many of the base-ten numerals for the positive integers less than or equal to $2017$ contain the digit $0$?
469
To solve this problem, we need to count the number of integers from 1 to 2017 that contain at least one digit '0'. We will break this down by the number of digits in the integers. 1. **One-digit integers (1 to 9):** - None of these integers contain the digit '0'. - Count: $0$ 2. **Two-digit integers (10 to 99):...
0.1875
7,625.1875
5,169
8,192
Determine the complex number $z$ satisfying the equation $2z-3i\bar{z}=-7+3i$. Note that $\bar{z}$ denotes the conjugate of $z$.
1+3i
1
2,082.4375
2,082.4375
-1
In a regular 15-gon, three distinct segments are chosen at random among the segments whose end-points are the vertices. What is the probability that the lengths of these three segments are the three side lengths of a triangle with positive area? A) $\frac{345}{455}$ B) $\frac{100}{455}$ C) $\frac{310}{455}$ D) $\frac{3...
\frac{345}{455}
0
8,192
-1
8,192
A and B each independently toss a fair coin. A tosses the coin 10 times, and B tosses the coin 11 times. What is the probability that the number of heads B gets is greater than the number of heads A gets?
1/2
0.125
7,982.6875
6,517.5
8,192
A package of seeds was passed around a table. The first person took 1 seed, the second person took 2 seeds, the third took 3 seeds, and so forth, with each subsequent person taking one more seed than the previous one. It is known that during the second round a total of 100 more seeds were taken than during the first ro...
10
0.0625
4,291.1875
7,241
4,094.533333
Point $P$ is located inside triangle $ABC$ so that angles $PAB, PBC,$ and $PCA$ are all congruent. The sides of the triangle have lengths $AB=13, BC=14,$ and $CA=15.$ Find $\tan \angle PAB.$
\frac{168}{295}
0.375
7,426.9375
6,151.833333
8,192
Three distinct numbers are selected simultaneously and at random from the set $\{1, 2, 3, 4, 5, 6, 7, 8, 9\}$. What is the probability that the smallest positive difference between any two of those numbers is $3$ or greater? Express your answer as a common fraction.
\frac{1}{14}
0
7,699.25
-1
7,699.25
Suppose $a$, $b$, and $c$ are real numbers, and the roots of the equation \[x^4 - 10x^3 + ax^2 + bx + c = 0\] are four distinct positive integers. Compute $a + b + c.$
109
0.1875
2,686.8125
2,030.666667
2,838.230769
Consider all permutations of the numbers $1, 2, \cdots, 8$ as eight-digit numbers. How many of these eight-digit numbers are multiples of 11?
4608
0.4375
6,830.1875
5,929.857143
7,530.444444
A wire is cut into two pieces: one of length $a$ bent to form a square, and another of length $b$ bent to form a regular octagon. The square and the octagon have equal areas. What is the ratio $\frac{a}{b}$?
\frac{\sqrt{2(1+\sqrt{2})}}{2}
0
7,174.625
-1
7,174.625
There is a strip with a length of 100, and each cell of the strip contains a chip. You can swap any two adjacent chips for 1 ruble, or you can swap any two chips that have exactly three chips between them for free. What is the minimum number of rubles needed to rearrange the chips in reverse order?
50
0
8,192
-1
8,192
How many four-digit positive integers are multiples of 7?
1286
0.9375
3,612.625
3,307.333333
8,192
Find the sum of the $x$-coordinates of the solutions to the system of equations $y=|x^2-8x+12|$ and $y=4-x$.
16
0.125
7,119.1875
3,884
7,581.357143
Given vectors $m=(\sqrt{3}\cos x,-1)$, $n=(\sin x,\cos ^{2}x)$. $(1)$ When $x=\frac{\pi}{3}$, find the value of $m\cdot n$; $(2)$ If $x\in\left[ 0,\frac{\pi}{4} \right]$, and $m\cdot n=\frac{\sqrt{3}}{3}-\frac{1}{2}$, find the value of $\cos 2x$.
\frac{3 \sqrt{2}- \sqrt{3}}{6}
0
6,144.8125
-1
6,144.8125
For all complex numbers $z$, let \[f(z) = \left\{ \begin{array}{cl} z^{2}&\text{ if }z\text{ is not real}, \\ -z^2 &\text{ if }z\text{ is real}. \end{array} \right.\]Find $f(f(f(f(1+i))))$.
-256
1
2,033.6875
2,033.6875
-1
In a finite sequence of real numbers the sum of any seven successive terms is negative and the sum of any eleven successive terms is positive. Determine the maximum number of terms in the sequence.
16
0
8,192
-1
8,192
When two fair dice are thrown, the numbers obtained are $a$ and $b$, respectively. Express the probability that the slope $k$ of the line $bx+ay=1$ is greater than or equal to $-\dfrac{2}{5}$.
\dfrac{1}{6}
1
5,486.5625
5,486.5625
-1
Calculate the lengths of arcs of curves given by equations in polar coordinates. $$ \rho = 3(1 + \sin \varphi), -\frac{\pi}{6} \leq \varphi \leq 0 $$
6(\sqrt{3} - \sqrt{2})
0.6875
5,930.875
5,591.090909
6,678.4
Given triangle ABC, where a, b, and c are the sides opposite to angles A, B, and C respectively, sin(2C - $\frac {π}{2}$) = $\frac {1}{2}$, and a<sup>2</sup> + b<sup>2</sup> < c<sup>2</sup>. (1) Find the measure of angle C. (2) Find the value of $\frac {a + b}{c}$.
\frac {2 \sqrt{3}}{3}
0
7,964.25
-1
7,964.25
Let \( f: \mathbb{N}^{*} \rightarrow \mathbb{N}^{*} \) be a function that satisfies the following conditions: 1. \( f(1)=1 \) 2. \( f(2n)=f(n) \) 3. \( f(2n+1)=f(n)+1 \) What is the greatest value of \( f(n) \) for \( 1 \leqslant n \leqslant 2018 \) ?
10
0.25
7,432.875
6,185.5
7,848.666667
Evaluate the expression $-20 + 15 \times (4^{\div -1} \times 2)$.
-12.5
0.8125
670.25
716.538462
469.666667
Painting the surface of a large metal ball requires 2.4 kilograms of paint. If this large metal ball is melted down to make 64 identical small metal balls, without considering any loss, the amount of paint needed to coat the surfaces of these small metal balls is \_\_\_\_\_\_ kilograms.
9.6
0.6875
3,621.875
4,733.636364
1,176
Given the coordinates of $A$, $B$, and $C$ are $A(4,0)$, $B(0,4)$, and $C(3\cos \alpha,3\sin \alpha)$ respectively: $(1)$ If $\alpha \in (-\pi,0)$ and $|\overrightarrow{AC}|=|\overrightarrow{BC}|$, find the value of $\alpha$; $(2)$ If $\overrightarrow{AC} \cdot \overrightarrow{BC}=0$, find the value of $\frac{2\sin...
-\frac{7}{16}
0.875
4,799.9375
4,315.357143
8,192
The exchange rate of the cryptocurrency Chukhoyn was one dollar on March 1, and then increased by one dollar each day. The exchange rate of the cryptocurrency Antonium was also one dollar on March 1, and then each day thereafter, it was equal to the sum of the previous day's rates of Chukhoyn and Antonium divided by th...
92/91
0.375
6,101.1875
3,478.5
7,674.8
Given that point $M$ lies on the circle $C:x^{2}+y^{2}-4x-14y+45=0$, and point $Q(-2,3)$. (1) If $P(a,a+1)$ is on circle $C$, find the length of segment $PQ$ and the slope of line $PQ$; (2) Find the maximum and minimum values of $|MQ|$; (3) If $M(m,n)$, find the maximum and minimum values of $\frac{n-{3}}{m+{2}}$.
2- \sqrt {3}
0
7,466.25
-1
7,466.25
In multiplying two positive integers $a$ and $b$, Ron reversed the digits of the two-digit number $a$. His erroneous product was $161$. What is the correct value of the product of $a$ and $b$?
224
1. **Identify the Error in Multiplication**: Ron reversed the digits of $a$ when multiplying. Let's denote the reversed number as $a'$. The erroneous product given is $161$, so we have $a' \cdot b = 161$. 2. **Factorize 161**: To find possible values of $a'$ and $b$, we factorize 161: \[ 161 = 7 \times 23 \] ...
0.8125
3,383.875
2,452.307692
7,420.666667
Define a new operation $\star$ such that for positive integers $a, b, c$, $a \star b \star c = \frac{a \times b + c}{a + b + c}$. Calculate the value of $4 \star 8 \star 2$. **A)** $\frac{34}{14}$ **B)** $\frac{16}{7}$ **C)** $\frac{17}{7}$ **D)** $\frac{32}{14}$ **E)** $2$
\frac{17}{7}
0.375
3,317.8125
443
5,042.7
Four people (A, B, C, D) are practicing passing a ball. The ball is initially passed by A, and each person who receives the ball has an equal probability of passing it to one of the other three people. Let \( p_{n} \) represent the probability that the ball returns to A after \( n \) passes. What is \( p_{6} \)?
\frac{61}{243}
0.5
6,561.875
4,931.75
8,192
A quadrilateral is inscribed in a circle with a radius of 13. The diagonals of the quadrilateral are perpendicular to each other. One of the diagonals is 18, and the distance from the center of the circle to the point where the diagonals intersect is \( 4 \sqrt{6} \). Find the area of the quadrilateral.
18 \sqrt{161}
0
7,919.5625
-1
7,919.5625
A regular triangular prism \(A B C A_{1} B_{1} C_{1}\) with base \(A B C\) and lateral edges \(A A_{1}, B B_{1}, C C_{1}\) is inscribed in a sphere. The segment \(C D\) is the diameter of this sphere, and point \(K\) is the midpoint of edge \(A A_{1}\). Find the volume of the prism if \(C K = 2 \sqrt{3}\) and \(D K = 2...
9\sqrt{2}
0.125
7,788.4375
5,152.5
8,165
Find the maximum value of the function $$ f(x) = \sqrt{3} \sin 2x + 2 \sin x + 4 \sqrt{3} \cos x. $$
\frac{17}{2}
0
8,192
-1
8,192
Let $a$ and $b$ be positive real numbers such that $3a^2 + 2b^2 = 3a + 2b$. Find the minimum value of $A =\sqrt{\frac{a}{b(3a+2)}} + \sqrt{\frac{b}{a(2b+3)}} $
\frac{2}{\sqrt{5}}
Let \( a \) and \( b \) be positive real numbers such that: \[ 3a^2 + 2b^2 = 3a + 2b. \] We aim to find the minimum value of: \[ A = \sqrt{\frac{a}{b(3a+2)}} + \sqrt{\frac{b}{a(2b+3)}}. \] First, observe the given equality: \[ 3a^2 + 2b^2 = 3a + 2b. \] Rearrange the terms: \[ 3a^2 - 3a + 2b^2 - 2b = 0. \] Rewr...
0
8,192
-1
8,192
An isosceles triangle and a rectangle have the same area. The base of the triangle is equal to the width of the rectangle, and this dimension is 10 units. The length of the rectangle is twice its width. What is the height of the triangle, $h$, in terms of the dimensions of the rectangle?
40
0.8125
5,081.125
4,485.076923
7,664
Compute $\sin 225^\circ$.
-\frac{\sqrt{2}}{2}
0
1,930.375
-1
1,930.375
$6^6 + 6^6 + 6^6 + 6^6 + 6^6 + 6^6 = $
$6^7$
1. **Identify the Expression**: The problem gives the expression $6^6 + 6^6 + 6^6 + 6^6 + 6^6 + 6^6$. 2. **Simplify the Expression**: We observe that the expression consists of six terms, each equal to $6^6$. This can be rewritten using the distributive property of multiplication over addition: \[ 6^6 + 6^6 + 6^...
0
929.5625
-1
929.5625
What is the maximum number of checkers that can be placed on a $6 \times 6$ board so that no three checkers (more precisely, the centers of the cells they occupy) are collinear (in any direction)?
12
0.1875
8,079.5
7,592
8,192
At a women's doubles tennis tournament, there were three teams of two women. After the tournament, each woman shook hands once with each of the other players except her partner. What is the number of handshakes that occurred?
12
1
3,986.9375
3,986.9375
-1
If $a \text{ Y } b$ is defined as $a \text{ Y } b = a^2 - 2ab + b^2$, what is the value of $3 \text{ Y } 2$?
1
1
1,570.1875
1,570.1875
-1
Given the conditions $a+acosC=\sqrt{3}csinA$, $\left(a+b+c\right)\left(a+b-c\right)=3ab$, $\left(a-b\right)\sin \left(B+C\right)+b\sin B=c\sin C$. Choose any one of these three conditions and complete the following question, then solve it. In triangle $\triangle ABC$, where the sides opposite angles $A$, $B$, and $C$ a...
6 + 4\sqrt{2}
0.6875
6,270.0625
5,480.363636
8,007.4
$P(x)$ is a polynomial of degree $3n$ such that \begin{eqnarray*} P(0) = P(3) = \cdots &=& P(3n) = 2, \\ P(1) = P(4) = \cdots &=& P(3n-2) = 1, \\ P(2) = P(5) = \cdots &=& P(3n-1) = 0, \quad\text{ and }\\ && P(3n+1) = 730.\end{eqnarray*} Determine $n$ .
\[ n = 4 \]
By Lagrange Interpolation Formula $f(x) = 2\sum_{p=0}^{n}\left ( \prod_{0\leq r\neq3p\leq 3n}^{{}}\frac{x-r}{3p-r} \right )+ \sum_{p=1}^{n}\left ( \prod_{0\leq r\neq3p-2\leq 3n}^{{}} \frac{x-r}{3p-2-r}\right )$ and hence $f(3n+1) = 2\sum_{p=0}^{n}\left ( \prod_{0\leq r\neq3p\leq 3n}^{{}}\frac{3n+1-r}{3p-r} \right )+ \...
0
8,192
-1
8,192
Given that the sum of the first $n$ terms of the sequence ${a_n}$ is $S_n$, and $S_{n}=n^{2}+n+1$. In the positive geometric sequence ${b_n}$, $b_3=a_2$, $b_4=a_4$. Find: 1. The general term formulas for ${a_n}$ and ${b_n}$; 2. If $c_n$ is defined as $c_n=\begin{cases} a_{n},(n\text{ is odd}) \\ b_{n},(n\text{ is even}...
733
0.5
5,707.5
5,284.75
6,130.25
Let $\triangle XYZ$ be a right triangle with $Y$ as a right angle. A circle with diameter $YZ$ intersects side $XZ$ at point $W$. If the area of $\triangle XYZ$ is $195$ and $XZ = 30$, find the length of $YW$.
13
0.875
5,331.125
4,922.428571
8,192
Carl only eats food in the shape of equilateral pentagons. Unfortunately, for dinner he receives a piece of steak in the shape of an equilateral triangle. So that he can eat it, he cuts off two corners with straight cuts to form an equilateral pentagon. The set of possible perimeters of the pentagon he obtains is exact...
4 \sqrt{3}-6
Assume that the triangle has side length 1. We will show the pentagon side length $x$ is in $\left[2 \sqrt{3}-3, \frac{1}{2}\right)$. Call the triangle $A B C$ and let corners $B, C$ be cut. Choose $P$ on $A B, Q, R$ on $B C$, and $S$ on $A C$ such that $A P Q R S$ is equilateral. If $x \geq \frac{1}{2}$ then $Q$ is to...
0
7,982.75
-1
7,982.75
There are 18 teams participating in the opening ceremony of a competition. When entering, the 1st team has 27 members, the 2nd team has 26 members, and the 18th team has 10 members. If they enter in a single file, and all 18 teams' members are assigned numbers from 1 to 333 in the order they enter, then the number of t...
10
0.3125
7,125.0625
5,276.6
7,965.272727
Convex quadrilateral \(ABCD\) is such that \(\angle BAC = \angle BDA\) and \(\angle BAD = \angle ADC = 60^\circ\). Find the length of \(AD\) given that \(AB = 14\) and \(CD = 6\).
20
0.0625
8,181
8,016
8,192
What is the area of the region defined by the equation $x^2 + y^2 - 3 = 6y - 18x + 9$?
102\pi
0.9375
2,075.625
2,100.333333
1,705
Given that $i$ is the imaginary unit, $a\in\mathbb{R}$, if $\frac{1-i}{a+i}$ is a pure imaginary number, calculate the modulus of the complex number $z=(2a+1)+ \sqrt{2}i$.
\sqrt{11}
1
2,152.125
2,152.125
-1
Given three points $A$, $B$, $C$ on a straight line in the Cartesian coordinate system, satisfying $\overrightarrow{OA}=(-3,m+1)$, $\overrightarrow{OB}=(n,3)$, $\overrightarrow{OC}=(7,4)$, and $\overrightarrow{OA} \perp \overrightarrow{OB}$, where $O$ is the origin. $(1)$ Find the values of the real numbers $m$, $n$; $...
-\frac{\sqrt{5}}{5}
0
6,631.4375
-1
6,631.4375