Found problems: 85335
2014 Contests, 1
If $\alpha$ and $\beta$ are the roots of the equation $3x^2+x-1=0$, where $\alpha>\beta$, find the value of $\frac{\alpha}{\beta}+\frac{\beta}{\alpha}$.
$ \textbf{(A) }\frac{7}{9}\qquad\textbf{(B) }-\frac{7}{9}\qquad\textbf{(C) }\frac{7}{3}\qquad\textbf{(D) }-\frac{7}{3}\qquad\textbf{(E) }-\frac{1}{9} $
2018 Malaysia National Olympiad, A4
Given points $A, B, C, D, E$, and $F$ on a line (not necessarily in that order) with $AB = 2$, $BC = 6$, $CD = 8$, $DE = 10$, $EF = 20$, and $FA = 22$. Find the distance between the two furthest points on the line.
2003 Mexico National Olympiad, 5
Some cards each have a pair of numbers written on them. There is just one card for each pair $(a,b)$ with $1 \leq a < b \leq 2003$. Two players play the following game. Each removes a card in turn and writes the product $ab$ of its numbers on the blackboard. The first player who causes the greatest common divisor of the numbers on the blackboard to fall to $1$ loses. Which player has a winning strategy?
2020-2021 OMMC, 2
The function $f(x)$ is defined on the reals such that
$$f\left(\frac{1-4x}{4-x}\right) = 4-xf(x)$$
for all $x \ne 4$. There exists two distinct real numbers $a, b \ne 4$ such that $f(a) = f(b) = \frac{5}{2}$. $a+b$ can be represented as $\frac{p}{q}$ where $p, q$ are relatively prime positive integers. Find $10p + q$.
2012 AIME Problems, 13
Three concentric circles have radii $3$, $4$, and $5$. An equilateral triangle with one vertex on each circle has side length $s$. The largest possible area of the triangle can be written as $a+\frac{b}{c}\sqrt{d}$, where $a,b,c$ and $d$ are positive integers, $b$ and $c$ are relatively prime, and $d$ is not divisible by the square of any prime. Find $a+b+c+d$.
2015 Junior Balkan MO, 3
Let $ABC$ be an acute triangle.The lines $l_1$ and $l_2$ are perpendicular to $AB$ at the points $A$ and $B$, respectively.The perpendicular lines from the midpoint $M$ of $AB$ to the lines $AC$ and $BC$ intersect $l_1$ and $l_2$ at the points $E$ and $F$, respectively.If $D$ is the intersection point of the lines $EF$ and $MC$, prove that \[\angle ADB = \angle EMF.\]
2022 CMWMC, R2
[u]Set 2[/u]
[b]2.1[/b] What is the last digit of $2022 + 2022^{2022} + 2022^{(2022^{2022})}$?
[b]2.2[/b] Let $T$ be the answer to the previous problem. CMIMC executive members are trying to arrange desks for CMWMC. If they arrange the desks into rows of $5$ desks, they end up with $1$ left over. If they instead arrange the desks into rows of $7$ desks, they also end up with $1$ left over. If they instead arrange the desks into rows of $11$ desks, they end up with $T$ left over. What is the smallest possible (non-negative) number of desks they could have?
[b]2.3[/b] Let $T$ be the answer to the previous problem. Compute the largest value of $k$ such that $11^k$ divides $$T! = T(T - 1)(T - 2)...(2)(1).$$
PS. You should use hide for answers.
1992 AMC 8, 10
An isosceles right triangle with legs of length $8$ is partitioned into $16$ congruent triangles as shown. The shaded area is
[asy]
for (int a=0; a <= 3; ++a)
{
for (int b=0; b <= 3-a; ++b)
{
fill((a,b)--(a,b+1)--(a+1,b)--cycle,grey);
}
}
for (int c=0; c <= 3; ++c)
{
draw((c,0)--(c,4-c),linewidth(1));
draw((0,c)--(4-c,c),linewidth(1));
draw((c+1,0)--(0,c+1),linewidth(1));
}
label("$8$",(2,0),S);
label("$8$",(0,2),W);
[/asy]
$\text{(A)}\ 10 \qquad \text{(B)}\ 20 \qquad \text{(C)}\ 32 \qquad \text{(D)}\ 40 \qquad \text{(E)}\ 64$
2024 Azerbaijan Senior NMO, 5
At the beginning of the academic year, the Olympic Center must accept a certain number of talented students for the 2024 different classes it offers. Although the admitted students are given freedom of choice in classes, there are certain rules. So, any student must take at least one class and cannot take all the classes. At the same time, there cannot be a common class that all students take, and any class must be taken by at least one student. As a final addition to the center's rules, for any student and any class that this student did not enroll in (call this type of class A), the number of students in each A must be greater than the number of classes this student enrolled. At least how many students must the center accept for these rules to be valid?
2009 Irish Math Olympiad, 5
Hello.
Suppose $a$, $b$, $c$ are real numbers such that $a+b+c = 0$ and $a^{2}+b^{2}+c^{2} = 1$.
Prove that $a^{2}b^{2}c^{2}\leq \frac{1}{54}$ and determine the cases of equality.
2014 PUMaC Geometry A, 8
$ABCD$ is a cyclic quadrilateral with circumcenter $O$ and circumradius $7$. $AB$ intersects $CD$ at $E$, $DA$ intersects $CB$ at $F$. $OE=13$, $OF=14$. Let $\cos\angle FOE=\dfrac pq$, with $p$, $q$ coprime. Find $p+q$.
1996 IMO, 4
The positive integers $ a$ and $ b$ are such that the numbers $ 15a \plus{} 16b$ and $ 16a \minus{} 15b$ are both squares of positive integers. What is the least possible value that can be taken on by the smaller of these two squares?
1981 National High School Mathematics League, 3
Let $\alpha$ be a real number and $\alpha\neq\frac{k\pi}{2} , k\in\mathbb{Z}$,
$$T=\frac{\sin\alpha+\tan\alpha}{\cos\alpha+\cot\alpha}$$.
$\text{(A)}$$T$ is negative.
$\text{(B)}$$T$ is nonnegative.
$\text{(C)}$$T$ is positive.
$\text{(D)}$$T$ can be either positive or negative.
2011 Sharygin Geometry Olympiad, 24
Given is an acute-angled triangle $ABC$. On sides $BC, CA, AB$, find points $A', B', C'$ such that the longest side of triangle $A'B'C'$ is minimal.
2009 All-Russian Olympiad Regional Round, 10.1
Square trinomial $f(x)$ is such that the polynomial $(f(x)) ^3- f(x)$ has exactly three real roots. Find the ordinate of the vertex of the graph of this trinomial.
2022 Indonesia MO, 1
Determine all functions $f: \mathbb{R} \to \mathbb{R}$ such that for any $x,y \in \mathbb{R}$ we have
\[ f(f(f(x)) + f(y)) = f(y) - f(x) \]
2017 Balkan MO Shortlist, N4
Find all pairs of positive integers $(x,y)$ , such that $x^2$ is divisible by $2xy^2 -y^3 +1$.
PEN P Problems, 31
A finite sequence of integers $a_{0}, a_{1}, \cdots, a_{n}$ is called quadratic if for each $i \in \{1,2,\cdots,n \}$ we have the equality $\vert a_{i}-a_{i-1} \vert = i^2$. [list=a] [*] Prove that for any two integers $b$ and $c$, there exists a natural number $n$ and a quadratic sequence with $a_{0}=b$ and $a_{n}=c$. [*] Find the smallest natural number $n$ for which there exists a quadratic sequence with $a_{0}=0$ and $a_{n}=1996$. [/list]
1985 AMC 12/AHSME, 16
If $ A \equal{} 20^{\circ}$ and $ B \equal{} 25^{\circ}$, then the value of $ (1 \plus{} \tan A)(1 \plus{} \tan B)$ is
$ \textbf{(A)} \sqrt3 \qquad \textbf{(B)}\ 2 \qquad \textbf{(C)}\ 1 \plus{} \sqrt2 \qquad \textbf{(D)}\ 2(\tan A \plus{} \tan B)$
$ \textbf{(E)}\ \text{ none of these}$
2003 Iran MO (3rd Round), 23
Find all homogeneous linear recursive sequences such that there is a $ T$ such that $ a_n\equal{}a_{n\plus{}T}$ for each $ n$.
2009 USAMTS Problems, 2
Let $a, b, c, d$ be four real numbers such that
\begin{align*}a + b + c + d &= 8, \\
ab + ac + ad + bc + bd + cd &= 12.\end{align*}
Find the greatest possible value of $d$.
2021 Korea - Final Round, P4
There are $n$($\ge 2$) clubs $A_1,A_2,...A_n$ in Korean Mathematical Society. Prove that there exist $n-1$ sets $B_1,B_2,...B_{n-1}$ that satisfy the condition below.
(1) $A_1\cup A_2\cup \cdots A_n=B_1\cup B_2\cup \cdots B_{n-1}$
(2) for any $1\le i<j\le n-1$, $B_i\cap B_j=\emptyset, -1\le\left\vert B_i \right\vert -\left\vert B_j \right\vert\le 1$
(3) for any $1\le i \le n-1$, there exist $A_k,A_j $($1\le k\le j\le n$)such that $B_i\subseteq A_k\cup A_j$
1988 Austrian-Polish Competition, 7
Each side of a regular octagon is colored blue or yellow. In each step, the sides are simultaneously recolored as follows: if the two neighbors of a side have different colors, the side will be recolored blue, otherwise it will be recolored yellow. Show that after a finite number of moves all sides will be colored yellow. What is the least value of the number $N$ of moves that always lead to all sides being yellow?
1996 All-Russian Olympiad Regional Round, 9.1
Find all pairs of square trinomials $x^2 + ax + b$, $ x^2 + cx + d$ such that $a$ and $b$ are the roots of the second trinomial, $c$ and $d$ are the roots of the first.
1999 Estonia National Olympiad, 5
There is a hole in the roof with dimensions $23 \times 19$ cm. Can August fill the the roof with tiles of dimensions $5 \times 24 \times 30$ cm?