High School Olympiads
Regional, national, and international math olympiads
Regional, national, and international math olympiads
3
M
G
BBookmark
VNew Topic
kLocked
High School Olympiads
Regional, national, and international math olympiads
Regional, national, and international math olympiads
3
M
G
BBookmark
VNew Topic
kLocked
No tags match your search
Mfunctional equation
algebra
combinatorics
geometry
inequalities
number theory
IMO
articles
inequalities proposed
function
algebra unsolved
circumcircle
trigonometry
number theory unsolved
inequalities unsolved
polynomial
geometry unsolved
geometry proposed
combinatorics unsolved
number theory proposed
functional equation
algebra proposed
modular arithmetic
induction
geometric transformation
incenter
calculus
3D geometry
combinatorics proposed
quadratics
Inequality
reflection
ratio
logarithms
prime numbers
analytic geometry
floor function
angle bisector
search
parallelogram
integration
Diophantine equation
rectangle
LaTeX
limit
complex numbers
probability
graph theory
conics
Euler
cyclic quadrilateral
No tags match your search
MG
Topic
First Poster
Last Poster
Funky function
TheUltimate123 24
N
an hour ago
by ezpotd
Source: CJMO 2022/5 (https://aops.com/community/c594864h2791269p24548889)
Find all functions
such that for all real numbers
and
, ![\[f(f(xy)+y)=(x+1)f(y).\]](//latex.artofproblemsolving.com/d/1/f/d1f369109456464bc8b0102763211802770d983d.png)
Proposed by novus677



![\[f(f(xy)+y)=(x+1)f(y).\]](http://latex.artofproblemsolving.com/d/1/f/d1f369109456464bc8b0102763211802770d983d.png)
Proposed by novus677
24 replies
Rolling Cube Combinatorics
KSH31415 0
Apr 24, 2025
Suppose
die is laid down on an infinite grid of
squares. The die starts perfectly aligned in one of the square of the grid with the
facing up and the
facing forward. The die can be "rolled" along an edge such that is moves exactly one unit up, down, left, or right and rotates
correspondingly in that axis.
Determine, with proof, all possible squares relative to the starting square for which it is possible to roll the die to that square and have it in the same orientation (
facing up and
facing forward).
(This problem may be hard to visualize/understand. If you don't understand the question, please ask and I can clarify.)





Determine, with proof, all possible squares relative to the starting square for which it is possible to roll the die to that square and have it in the same orientation (


(This problem may be hard to visualize/understand. If you don't understand the question, please ask and I can clarify.)
0 replies
PIE Help
Rice_Farmer 5
N
Mar 19, 2025
by Rice_Farmer
How many ways are there to color the
regions of a three-set Venn Diagram with
colors such that each color is used at least once? Two colorings are considered the same if one can be reached from the other by rotation and reflection.
Non ai way btw pls


Non ai way btw pls
5 replies
Simple Combinatorics on seating in a circle
duttaditya18 6
N
Mar 6, 2025
by S_14159
Five persons wearing badges with numbers
are seated on
chairs around a circular table. In how many ways can they be seated so that no two persons whose badges have consecutive numbers are seated next to each other? (Two arrangements obtained by rotation around the table are considered different)


6 replies
[PMO25 Qualifying I.14] Grid Division
kae_3 0
Feb 23, 2025
How many ways are there to divide a
square into three rectangles, all of whose sides are integers? Assume that two configurations which are obtained by either a rotation and/or a reflection are considered the same.

Answer Confirmation


Answer Confirmation

0 replies
extended ray to get a desired angle & ratio
SYBARUPEMULA 2
N
Feb 5, 2025
by SYBARUPEMULA
Given triangle
. Points
and
at segment
and
respectively such that
and
. The ray
is extended to point
such that 

. It's given
, compute
.














2 replies
Questions about angle notation
tsun26 2
N
Jan 13, 2025
by AbhayAttarde01
What's the difference between writing
and
?


2 replies
Line of slope i
eduD_looC 1
N
Dec 19, 2024
by MineCuber
What happens when you rotate a line of slope
by
degrees? All I've got is that if
, then the new line should still have slope
since
. :/
On a second thought, is it even possible to rotate such a line?
I remember reading about this because "five points determine a conic" and "three points are sufficient to determine a circle". So there are two special points on all circles (smth like that).





On a second thought, is it even possible to rotate such a line?
I remember reading about this because "five points determine a conic" and "three points are sufficient to determine a circle". So there are two special points on all circles (smth like that).
1 reply
Escape from the genie
talkinaway 8
N
Oct 28, 2024
by parmenides51
A genie has tied and blindfolded you, and has placed four coins in front of you on a square plate's vertices - the coins do not start out all heads or all tails.
The genie makes a deal with you: When the coins are all heads or all tails, he will release you, but until then, you are bound and blindfolded. You may turn any number of coins you like, and say "ALAKAZAM" to indicate you are ready for the genie to inspect the coins. The genie will inspect the coins, and will either free you (if the coins are right), or will rotate the table
degrees - you won't know which.
After he rotates the table, you may flip coins again, and shout "ALAKAZAM" again. You may repeat this as many times as you wish.
You realize that there's a way to escape - and this way to escape requires you shouting "ALAKAZAM" at most
times. Find the minimal value of
, and describe the strategy.
The genie makes a deal with you: When the coins are all heads or all tails, he will release you, but until then, you are bound and blindfolded. You may turn any number of coins you like, and say "ALAKAZAM" to indicate you are ready for the genie to inspect the coins. The genie will inspect the coins, and will either free you (if the coins are right), or will rotate the table

After he rotates the table, you may flip coins again, and shout "ALAKAZAM" again. You may repeat this as many times as you wish.
You realize that there's a way to escape - and this way to escape requires you shouting "ALAKAZAM" at most


8 replies
Knights at the Round Table
mathkid 48
N
Sep 29, 2024
by ehuseyinyigit
Twenty five of King Arthur's knights are seated at their customary round table. Three of them are chosen - all choices of three being equally likely - and are sent off to slay a troublesome dragon. Let
be the probability that at least two of the three had been sitting next to each other. If
is written as a fraction in lowest terms, what is the sum of the numerator and denominator?


48 replies
decimal notation
FirstUndertale 1
N
Aug 10, 2024
by Iwowowl253
Consider the real number, written in decimal notation,
![\[ r = 0.235831\ldots \]](//latex.artofproblemsolving.com/d/d/f/ddfd2ca87cb8716d69c8dded5e522f0f5757a61e.png)
where, starting from the third decimal place after the comma, each digit is equal to the remainder when the sum of the two previous digits is divided by 10. We can state that:
(a)
is an integer
(b)
is an integer
(c)
is an integer
(d)
is an algebraic irrational number
(e)
is a transcendental (non-algebraic) irrational number
![\[ r = 0.235831\ldots \]](http://latex.artofproblemsolving.com/d/d/f/ddfd2ca87cb8716d69c8dded5e522f0f5757a61e.png)
where, starting from the third decimal place after the comma, each digit is equal to the remainder when the sum of the two previous digits is divided by 10. We can state that:
(a)

(b)

(c)

(d)

(e)

1 reply
