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Contests & Programs AMC and other contests, summer programs, etc.
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k a June Highlights and 2025 AoPS Online Class Information
jlacosta   0
Jun 2, 2025
Congratulations to all the mathletes who competed at National MATHCOUNTS! If you missed the exciting Countdown Round, you can watch the video at this link. Are you interested in training for MATHCOUNTS or AMC 10 contests? How would you like to train for these math competitions in half the time? We have accelerated sections which meet twice per week instead of once starting on July 8th (7:30pm ET). These sections fill quickly so enroll today!

[list][*]MATHCOUNTS/AMC 8 Basics
[*]MATHCOUNTS/AMC 8 Advanced
[*]AMC 10 Problem Series[/list]
For those interested in Olympiad level training in math, computer science, physics, and chemistry, be sure to enroll in our WOOT courses before August 19th to take advantage of early bird pricing!

Summer camps are starting this month at the Virtual Campus in math and language arts that are 2 - to 4 - weeks in duration. Spaces are still available - don’t miss your chance to have a transformative summer experience. There are middle and high school competition math camps as well as Math Beasts camps that review key topics coupled with fun explorations covering areas such as graph theory (Math Beasts Camp 6), cryptography (Math Beasts Camp 7-8), and topology (Math Beasts Camp 8-9)!

Be sure to mark your calendars for the following upcoming events:
[list][*]June 5th, Thursday, 7:30pm ET: Open Discussion with Ben Kornell and Andrew Sutherland, Art of Problem Solving's incoming CEO Ben Kornell and CPO Andrew Sutherland host an Ask Me Anything-style chat. Come ask your questions and get to know our incoming CEO & CPO!
[*]June 9th, Monday, 7:30pm ET, Game Jam: Operation Shuffle!, Come join us to play our second round of Operation Shuffle! If you enjoy number sense, logic, and a healthy dose of luck, this is the game for you. No specific math background is required; all are welcome.[/list]
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0 replies
1 viewing
jlacosta
Jun 2, 2025
0 replies
k i Adding contests to the Contest Collections
dcouchman   1
N Apr 5, 2023 by v_Enhance
Want to help AoPS remain a valuable Olympiad resource? Help us add contests to AoPS's Contest Collections.

Find instructions and a list of contests to add here: https://artofproblemsolving.com/community/c40244h1064480_contests_to_add
1 reply
dcouchman
Sep 9, 2019
v_Enhance
Apr 5, 2023
k i Zero tolerance
ZetaX   49
N May 4, 2019 by NoDealsHere
Source: Use your common sense! (enough is enough)
Some users don't want to learn, some other simply ignore advises.
But please follow the following guideline:


To make it short: ALWAYS USE YOUR COMMON SENSE IF POSTING!
If you don't have common sense, don't post.


More specifically:

For new threads:


a) Good, meaningful title:
The title has to say what the problem is about in best way possible.
If that title occured already, it's definitely bad. And contest names aren't good either.
That's in fact a requirement for being able to search old problems.

Examples:
Bad titles:
- "Hard"/"Medium"/"Easy" (if you find it so cool how hard/easy it is, tell it in the post and use a title that tells us the problem)
- "Number Theory" (hey guy, guess why this forum's named that way¿ and is it the only such problem on earth¿)
- "Fibonacci" (there are millions of Fibonacci problems out there, all posted and named the same...)
- "Chinese TST 2003" (does this say anything about the problem¿)
Good titles:
- "On divisors of a³+2b³+4c³-6abc"
- "Number of solutions to x²+y²=6z²"
- "Fibonacci numbers are never squares"


b) Use search function:
Before posting a "new" problem spend at least two, better five, minutes to look if this problem was posted before. If it was, don't repost it. If you have anything important to say on topic, post it in one of the older threads.
If the thread is locked cause of this, use search function.

Update (by Amir Hossein). The best way to search for two keywords in AoPS is to input
[code]+"first keyword" +"second keyword"[/code]
so that any post containing both strings "first word" and "second form".


c) Good problem statement:
Some recent really bad post was:
[quote]$lim_{n\to 1}^{+\infty}\frac{1}{n}-lnn$[/quote]
It contains no question and no answer.
If you do this, too, you are on the best way to get your thread deleted. Write everything clearly, define where your variables come from (and define the "natural" numbers if used). Additionally read your post at least twice before submitting. After you sent it, read it again and use the Edit-Button if necessary to correct errors.


For answers to already existing threads:


d) Of any interest and with content:
Don't post things that are more trivial than completely obvious. For example, if the question is to solve $x^{3}+y^{3}=z^{3}$, do not answer with "$x=y=z=0$ is a solution" only. Either you post any kind of proof or at least something unexpected (like "$x=1337, y=481, z=42$ is the smallest solution). Someone that does not see that $x=y=z=0$ is a solution of the above without your post is completely wrong here, this is an IMO-level forum.
Similar, posting "I have solved this problem" but not posting anything else is not welcome; it even looks that you just want to show off what a genius you are.

e) Well written and checked answers:
Like c) for new threads, check your solutions at least twice for mistakes. And after sending, read it again and use the Edit-Button if necessary to correct errors.



To repeat it: ALWAYS USE YOUR COMMON SENSE IF POSTING!


Everything definitely out of range of common sense will be locked or deleted (exept for new users having less than about 42 posts, they are newbies and need/get some time to learn).

The above rules will be applied from next monday (5. march of 2007).
Feel free to discuss on this here.
49 replies
ZetaX
Feb 27, 2007
NoDealsHere
May 4, 2019
MAN IS KID
DrMath   138
N 13 minutes ago by ihatemath123
Source: USAMO 2017 P3, Evan Chen
Let $ABC$ be a scalene triangle with circumcircle $\Omega$ and incenter $I$. Ray $AI$ meets $\overline{BC}$ at $D$ and meets $\Omega$ again at $M$; the circle with diameter $\overline{DM}$ cuts $\Omega$ again at $K$. Lines $MK$ and $BC$ meet at $S$, and $N$ is the midpoint of $\overline{IS}$. The circumcircles of $\triangle KID$ and $\triangle MAN$ intersect at points $L_1$ and $L_2$. Prove that $\Omega$ passes through the midpoint of either $\overline{IL_1}$ or $\overline{IL_2}$.

Proposed by Evan Chen
138 replies
1 viewing
DrMath
Apr 19, 2017
ihatemath123
13 minutes ago
2n equations
P_Groudon   84
N 33 minutes ago by DeathIsAwe
Let $n \geq 4$ be an integer. Find all positive real solutions to the following system of $2n$ equations:

\begin{align*}
a_{1} &=\frac{1}{a_{2 n}}+\frac{1}{a_{2}}, & a_{2}&=a_{1}+a_{3}, \\
a_{3}&=\frac{1}{a_{2}}+\frac{1}{a_{4}}, & a_{4}&=a_{3}+a_{5}, \\
a_{5}&=\frac{1}{a_{4}}+\frac{1}{a_{6}}, & a_{6}&=a_{5}+a_{7} \\
&\vdots & &\vdots \\
a_{2 n-1}&=\frac{1}{a_{2 n-2}}+\frac{1}{a_{2 n}}, & a_{2 n}&=a_{2 n-1}+a_{1}
\end{align*}
84 replies
P_Groudon
Apr 15, 2021
DeathIsAwe
33 minutes ago
USA 97 [1/(b^3+c^3+abc) + ... >= 1/(abc)]
Maverick   48
N an hour ago by SomeonecoolLovesMaths
Source: USAMO 1997/5; also: ineq E2.37 in Book: Inegalitati; Authors:L.Panaitopol,V. Bandila,M.Lascu
Prove that, for all positive real numbers $ a$, $ b$, $ c$, the inequality
\[ \frac {1}{a^3 + b^3 + abc} + \frac {1}{b^3 + c^3 + abc} + \frac {1}{c^3 + a^3 + abc} \leq \frac {1}{abc}
\]
holds.
48 replies
Maverick
Sep 12, 2003
SomeonecoolLovesMaths
an hour ago
Frustration with Olympiad Geo
gulab_jamun   21
N an hour ago by CuriousMathBoy72
Ok, so right now, I am doing the EGMO book by Evan Chen, but when it comes to problems, there are some that just genuinely frustrate me and I don't know how to deal with them. For example, I've spent 1.5 hrs on the second to last question in chapter 2, and used all the hints, and I still am stuck. It just frustrates me incredibly. Any tips on managing this? (or.... am I js crashing out too much?)
21 replies
gulab_jamun
May 29, 2025
CuriousMathBoy72
an hour ago
Parabola Rotation
YaoAOPS   56
N an hour ago by G_and3Ms
Source: 2025 AIME I #9
The parabola with equation $y = x^2 - 4$ is rotated $60^\circ$ counterclockwise around the origin. The unique point in the fourth quadrant where the original parabola and its image intersect has $y$-coordinate $\frac{a - \sqrt{b}}{c}$, where $a$, $b$, and $c$ are positive integers, and $a$ and $c$ are relatively prime. Find $a + b + c$.
56 replies
YaoAOPS
Feb 7, 2025
G_and3Ms
an hour ago
Hi inequalities
bjump   4
N an hour ago by SomeonecoolLovesMaths
Source: OTIS, Kyle Wu
For positive real numbers $a$, $b$, and $c$ with $a+b+c=1$ prove that
$$\frac{b^{2}+c^{2}}{1+a}+\frac{c^{2}+a^{2}}{1+b}+ \frac{a^{2}+b^{2}}{1+c} \geq \frac{1}{2}$$
4 replies
bjump
Jan 21, 2024
SomeonecoolLovesMaths
an hour ago
Replacing OH with any line through the centroid G???
Sid-darth-vater   3
N an hour ago by oolite
Source: APMO 2004/2
Let $O$ be the circumcenter and $H$ the orthocenter of an acute triangle $ABC.$ Prove that the area of one of the triangles $AOH, BOH,$ and $COH$ is equal to the sum of the areas of the other two.

Basically, I was able to solve this question using the centroid but without moving line OH.
Here is a quick sketch of what I did: All triangles have base of OH so you just have to show that two altitudes to line OH add up to the third. WLOG, let triangle AOH have the largest area and let A', B', C' denote altitudes from their respective points to line OH. This is euler line so G also lies on OH. Let AG instersect BC at M (which is a median) and let M' denote altitude onto OH. Note that M'M = 0.5 * AA' and since BCC'B' is trapezoid and M is midpoint, MM' = 0.5 (BB' + CC') so equate the two and we are done.

In Evan Chen's EGMO book, he says you can replace line $OH$ with any line through the centroid $G$ and I have no clue as to why that is true. Plz help
3 replies
Sid-darth-vater
4 hours ago
oolite
an hour ago
Functional xf(x+f(y))=(y-x)f(f(x)) for all reals x,y
cretanman   61
N an hour ago by HDavisWashu
Source: BMO 2023 Problem 1
Find all functions $f\colon \mathbb{R} \rightarrow \mathbb{R}$ such that for all $x,y \in \mathbb{R}$,
\[xf(x+f(y))=(y-x)f(f(x)).\]
Proposed by Nikola Velov, Macedonia
61 replies
cretanman
May 10, 2023
HDavisWashu
an hour ago
Increments and Decrements in Square Grid
ike.chen   24
N an hour ago by fearsum_fyz
Source: ISL 2022/C3
In each square of a garden shaped like a $2022 \times 2022$ board, there is initially a tree of height $0$. A gardener and a lumberjack alternate turns playing the following game, with the gardener taking the first turn:
[list]
[*] The gardener chooses a square in the garden. Each tree on that square and all the surrounding squares (of which there are at most eight) then becomes one unit taller.
[*] The lumberjack then chooses four different squares on the board. Each tree of positive height on those squares then becomes one unit shorter.
[/list]
We say that a tree is majestic if its height is at least $10^6$. Determine the largest $K$ such that the gardener can ensure there are eventually $K$ majestic trees on the board, no matter how the lumberjack plays.
24 replies
ike.chen
Jul 9, 2023
fearsum_fyz
an hour ago
Weirdly stated but cool collinearity
Rijul saini   5
N 2 hours ago by ihategeo_1969
Source: LMAO Revenge 2025 Day 1 Problem 2
Let Mary choose any non-degenerate $\triangle ABC$. Let $I$ be its incenter, $I_A$ be its $A$-excenter, $N_A$ be midpoint of arc $BAC$, $M$ is the midpoint of $BC$.

Let $H \neq I$ be the intersection of the line $N_AI$ with $(BIC)$, $F$ be the intersection of the angle bisector of $\angle BAC$ with the line $BC$.

Ana now draws the points $P \neq H$ ,the intersection of line $I_AH$ with $(HIF)$ and $Q$ ,the intersection of $(HIM)$ and $(AN_AI_A)$ such that $I_AH < I_AQ$. Ana wins if the points $A, P, Q$ are collinear. Who has a winning strategy?
5 replies
Rijul saini
Jun 4, 2025
ihategeo_1969
2 hours ago
old and easy imo inequality
Valentin Vornicu   217
N 2 hours ago by SomeonecoolLovesMaths
Source: IMO 2000, Problem 2, IMO Shortlist 2000, A1
Let $ a, b, c$ be positive real numbers so that $ abc = 1$. Prove that
\[ \left( a - 1 + \frac 1b \right) \left( b - 1 + \frac 1c \right) \left( c - 1 + \frac 1a \right) \leq 1.
\]
217 replies
Valentin Vornicu
Oct 24, 2005
SomeonecoolLovesMaths
2 hours ago
One of the lines is tangent
Rijul saini   9
N 2 hours ago by Captainscrubz
Source: LMAO 2025 Day 2 Problem 2
Let $ABC$ be a scalene triangle with incircle $\omega$. Denote by $N$ the midpoint of arc $BAC$ in the circumcircle of $ABC$, and by $D$ the point where the $A$-excircle touches $BC$. Suppose the circumcircle of $AND$ meets $BC$ again at $P \neq D$ and intersects $\omega$ at two points $X$, $Y$.

Prove that either $PX$ or $PY$ is tangent to $\omega$.

Proposed by Sanjana Philo Chacko
9 replies
Rijul saini
Jun 4, 2025
Captainscrubz
2 hours ago
Cyclic Quadrilateral in a Square
tobiSALT   3
N 2 hours ago by Sid-darth-vater
Source: Cono Sur 2025 #1
Given a square $ABCD$, let $P$ be a point on the segment $BC$ and let $G$ be the intersection point of $AP$ with the diagonal $DB$. The line perpendicular to the segment $AP$ through $G$ intersects the side $CD$ at point $E$. Let $K$ be a point on the segment $GE$ such that $AK = PE$. Let $Q$ be the intersection point of the diagonal $AC$ and the segment $KP$.
Prove that the points $E, K, Q,$ and $C$ are concyclic.
3 replies
tobiSALT
3 hours ago
Sid-darth-vater
2 hours ago
Very easy number theory
darij grinberg   103
N 2 hours ago by Siddharthmaybe
Source: IMO Shortlist 2000, N1, 6th Kolmogorov Cup, 1-8 December 2002, 1st round, 1st league,
Determine all positive integers $ n\geq 2$ that satisfy the following condition: for all $ a$ and $ b$ relatively prime to $ n$ we have \[a \equiv b \pmod n\qquad\text{if and only if}\qquad ab\equiv 1 \pmod n.\]
103 replies
darij grinberg
Aug 6, 2004
Siddharthmaybe
2 hours ago
Mock Olympiad Geometry Contest #3
wu2481632   104
N Dec 2, 2017 by wu2481632
"If it is GGG, it will be GG..."

Hi everyone! Over the last few weeks, I have had the pleasure of creating another olympiad geometry contest. My first one can be found here and my second one can be found here.

I believe the contest is somewhere between the USAJMO and USAMO in difficulty.

Sign up for the contest by posting in the thread, please. The contest will be released in approximately a week, after testsolvers have finished looking over it.

I'd like to thank users Generic_Username, AlgebraFC, MathSlayer4444, InCtrl, champion999, joey8189681, brainiac1 for being there to support me in the creation of this contest. As well as complaining about the difficulty of drawing the diagrams, they also provided moral support and, in some cases, testsolved problems.

I only currently have three testsolvers, so I would like at least one more to guarantee quality; message me or post in-thread if you would like to testsolve. I have enough testsolvers now, yay! I'm also really lazy and still haven't properly learned enough bash (I only know the basics of complex and bary) so signups for grading bashes would be really, really appreciated.

Test deadline is December 1.

Current Testsolvers

See this post about time limits.

Signups for grading bashes

Submission Rules

Day I Leaderboard

Day II Leaderboard

Complete Leaderboard
104 replies
wu2481632
Oct 7, 2017
wu2481632
Dec 2, 2017
Mock Olympiad Geometry Contest #3
G H J
G H BBookmark kLocked kLocked NReply
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wu2481632
4239 posts
#1 • 52 Y
Y by Generic_Username, KateL, anantmudgal09, checkmatetang, PiDude314, niyu, brainiac1, skipiano, yegkatie, WireCat, Kagebaka, soojoong, Vfire, atmchallenge, AIME12345, SAUDITYA, Assmit, tenplusten, Mudkipswims42, FedeX333X, RamanConjecture, mira74, GeneralCobra19, oceanair, SAM8, qwerty733, roseylily, laegolas, thedoge, Snakes, franchester, DrMath, Plasma_Vortex, 62861, pifinity, jangkun217, bluephoenix, enhanced, N.G_using_P.G, speck, mukes070304, bigmath, targo___, Aryan-23, amar_04, AmirKhusrau, OlympusHero, Toinfinity, myh2910, parmenides51, centslordm, Adventure10
"If it is GGG, it will be GG..."

Hi everyone! Over the last few weeks, I have had the pleasure of creating another olympiad geometry contest. My first one can be found here and my second one can be found here.

I believe the contest is somewhere between the USAJMO and USAMO in difficulty.

Sign up for the contest by posting in the thread, please. The contest will be released in approximately a week, after testsolvers have finished looking over it.

I'd like to thank users Generic_Username, AlgebraFC, MathSlayer4444, InCtrl, champion999, joey8189681, brainiac1 for being there to support me in the creation of this contest. As well as complaining about the difficulty of drawing the diagrams, they also provided moral support and, in some cases, testsolved problems.

I only currently have three testsolvers, so I would like at least one more to guarantee quality; message me or post in-thread if you would like to testsolve. I have enough testsolvers now, yay! I'm also really lazy and still haven't properly learned enough bash (I only know the basics of complex and bary) so signups for grading bashes would be really, really appreciated.

Test deadline is December 1.

Current Testsolvers

See this post about time limits.

Signups for grading bashes

Submission Rules

Day I Leaderboard

Day II Leaderboard

Complete Leaderboard
Attachments:
day 2.pdf (82kb)
day 1.pdf (89kb)
This post has been edited 19 times. Last edited by wu2481632, Dec 2, 2017, 3:11 PM
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leequack
1006 posts
#2 • 1 Y
Y by Adventure10
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itised
1720 posts
#3 • 1 Y
Y by Adventure10
Grading bashes... bwahahahaha

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This post has been edited 1 time. Last edited by itised, Oct 7, 2017, 10:19 PM
Reason: 1 + 1 = 1
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niyu
830 posts
#4 • 2 Y
Y by Adventure10, Mango247
Signups(3)

Totally pumped for this :D
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brainiac1
2837 posts
#5 • 2 Y
Y by Adventure10, Mango247
wu2481632 wrote:
I'd like to thank users Generic_Username, AlgebraFC, MathSlayer4444, InCtrl, champion999, joey8189681, braniac1 for being there to support me in the creation of this contest. As well as complaining about the difficulty of drawing the diagrams, they also provided moral support and, in some cases, testsolved problems.

:angery:
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skipiano
1860 posts
#6 • 2 Y
Y by Adventure10, Mango247
brainiac1 wrote:
wu2481632 wrote:
I'd like to thank users Generic_Username, AlgebraFC, MathSlayer4444, InCtrl, champion999, joey8189681, braniac1 for being there to support me in the creation of this contest. As well as complaining about the difficulty of drawing the diagrams, they also provided moral support and, in some cases, testsolved problems.

:angery:

What are you angry about, bran is very good for your health :D
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wu2481632
4239 posts
#7 • 2 Y
Y by Adventure10, Mango247
brainiac1 wrote:
wu2481632 wrote:
I'd like to thank users Generic_Username, AlgebraFC, MathSlayer4444, InCtrl, champion999, joey8189681, braniac1 for being there to support me in the creation of this contest. As well as complaining about the difficulty of drawing the diagrams, they also provided moral support and, in some cases, testsolved problems.

:angery:

My sincerest apologies. I have fixed the error.
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RC.
439 posts
#9 • 2 Y
Y by Adventure10, Mango247
Signups(4)
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Vfire
1354 posts
#10 • 2 Y
Y by Adventure10, Mango247
Oooh sounds like fun!

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AlgebraFC
512 posts
#11 • 5 Y
Y by wu2481632, Mudkipswims42, OlympusHero, Adventure10, Mango247
I'll signup again for grading bashes but last time I received none to grade :|
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Hydrogen-Helium
173 posts
#12 • 2 Y
Y by Adventure10, Mango247
Signups(6)

let's bash lots of problems haha idk
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CoulombNumberFun
423 posts
#13 • 2 Y
Y by Adventure10, Mango247
..........
This post has been edited 1 time. Last edited by CoulombNumberFun, Oct 8, 2017, 4:20 AM
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atmchallenge
980 posts
#14 • 5 Y
Y by AlgebraFC, Mudkipswims42, MithilShah, Adventure10, Mango247
AlgebraFC wrote:
I'll signup again for grading bashes but last time I received none to grade :|

Don't worry :P

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This post has been edited 1 time. Last edited by atmchallenge, Oct 8, 2017, 1:38 AM
Reason: can't count... hopefully I can do geo
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bigbread42
104 posts
#16 • 1 Y
Y by Adventure10
Signups(9)
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MarkBcc168
1595 posts
#17 • 3 Y
Y by wu2481632, don2001, Adventure10
Is the test-solver spot currently full? If not I can sign up.
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