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k a My Retirement & New Leadership at AoPS
rrusczyk   1571
N Mar 26, 2025 by SmartGroot
I write today to announce my retirement as CEO from Art of Problem Solving. When I founded AoPS 22 years ago, I never imagined that we would reach so many students and families, or that we would find so many channels through which we discover, inspire, and train the great problem solvers of the next generation. I am very proud of all we have accomplished and I’m thankful for the many supporters who provided inspiration and encouragement along the way. I'm particularly grateful to all of the wonderful members of the AoPS Community!

I’m delighted to introduce our new leaders - Ben Kornell and Andrew Sutherland. Ben has extensive experience in education and edtech prior to joining AoPS as my successor as CEO, including starting like I did as a classroom teacher. He has a deep understanding of the value of our work because he’s an AoPS parent! Meanwhile, Andrew and I have common roots as founders of education companies; he launched Quizlet at age 15! His journey from founder to MIT to technology and product leader as our Chief Product Officer traces a pathway many of our students will follow in the years to come.

Thank you again for your support for Art of Problem Solving and we look forward to working with millions more wonderful problem solvers in the years to come.

And special thanks to all of the amazing AoPS team members who have helped build AoPS. We’ve come a long way from here:IMAGE
1571 replies
rrusczyk
Mar 24, 2025
SmartGroot
Mar 26, 2025
k a March Highlights and 2025 AoPS Online Class Information
jlacosta   0
Mar 2, 2025
March is the month for State MATHCOUNTS competitions! Kudos to everyone who participated in their local chapter competitions and best of luck to all going to State! Join us on March 11th for a Math Jam devoted to our favorite Chapter competition problems! Are you interested in training for MATHCOUNTS? Be sure to check out our AMC 8/MATHCOUNTS Basics and Advanced courses.

Are you ready to level up with Olympiad training? Registration is open with early bird pricing available for our WOOT programs: MathWOOT (Levels 1 and 2), CodeWOOT, PhysicsWOOT, and ChemWOOT. What is WOOT? WOOT stands for Worldwide Online Olympiad Training and is a 7-month high school math Olympiad preparation and testing program that brings together many of the best students from around the world to learn Olympiad problem solving skills. Classes begin in September!

Do you have plans this summer? There are so many options to fit your schedule and goals whether attending a summer camp or taking online classes, it can be a great break from the routine of the school year. Check out our summer courses at AoPS Online, or if you want a math or language arts class that doesn’t have homework, but is an enriching summer experience, our AoPS Virtual Campus summer camps may be just the ticket! We are expanding our locations for our AoPS Academies across the country with 15 locations so far and new campuses opening in Saratoga CA, Johns Creek GA, and the Upper West Side NY. Check out this page for summer camp information.

Be sure to mark your calendars for the following events:
[list][*]March 5th (Wednesday), 4:30pm PT/7:30pm ET, HCSSiM Math Jam 2025. Amber Verser, Assistant Director of the Hampshire College Summer Studies in Mathematics, will host an information session about HCSSiM, a summer program for high school students.
[*]March 6th (Thursday), 4:00pm PT/7:00pm ET, Free Webinar on Math Competitions from elementary through high school. Join us for an enlightening session that demystifies the world of math competitions and helps you make informed decisions about your contest journey.
[*]March 11th (Tuesday), 4:30pm PT/7:30pm ET, 2025 MATHCOUNTS Chapter Discussion MATH JAM. AoPS instructors will discuss some of their favorite problems from the MATHCOUNTS Chapter Competition. All are welcome!
[*]March 13th (Thursday), 4:00pm PT/7:00pm ET, Free Webinar about Summer Camps at the Virtual Campus. Transform your summer into an unforgettable learning adventure! From elementary through high school, we offer dynamic summer camps featuring topics in mathematics, language arts, and competition preparation - all designed to fit your schedule and ignite your passion for learning.[/list]
Our full course list for upcoming classes is below:
All classes run 7:30pm-8:45pm ET/4:30pm - 5:45pm PT unless otherwise noted.

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0 replies
jlacosta
Mar 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
Where can I find korean TST problems?
jjkim0336   2
N 29 minutes ago by aidenkim119
I can’t find it anywhere
2 replies
jjkim0336
Nov 26, 2024
aidenkim119
29 minutes ago
inequalities
Cobedangiu   1
N 30 minutes ago by Cobedangiu
problem
1 reply
1 viewing
Cobedangiu
3 hours ago
Cobedangiu
30 minutes ago
aops ids
Bummer12345   80
N 38 minutes ago by SpeedCuber7
Make your argument here on why your AoPS user ID is the coolest!!!!! :pilot: :pilot: :pilot: :pilot: :pilot:

For instance, my ID, $573803$, can be written as $547 \cdot 1049$, both which are prime.

$547$ is a cuban prime, prime index prime

$1049$ is a Sophie Germain prime

I think my ID is pretty cool, but theres probably better IDs out there.

stuff
80 replies
Bummer12345
Mar 28, 2025
SpeedCuber7
38 minutes ago
Sum_cyc ab / a^2+3b^2 < = 3/4
Kunihiko_Chikaya   10
N 41 minutes ago by sqing
Let $a,\ b,\ c$ be positive real numbers.
Prove that :
\[\frac{ab}{a^2+3b^2}+\frac{bc}{b^2+3c^2}+\frac{ca}{c^2+3a^2}\leq \frac 34.\]
10 replies
Kunihiko_Chikaya
Jul 6, 2014
sqing
41 minutes ago
Three circles are concurrent
Twoisaprime   22
N an hour ago by HoRI_DA_GRe8
Source: RMM 2025 P5
Let triangle $ABC$ be an acute triangle with $AB<AC$ and let $H$ and $O$ be its orthocenter and circumcenter, respectively. Let $\Gamma$ be the circle $BOC$. The line $AO$ and the circle of radius $AO$ centered at $A$ cross $\Gamma$ at $A’$ and $F$, respectively. Prove that $\Gamma$ , the circle on diameter $AA’$ and circle $AFH$ are concurrent.
Proposed by Romania, Radu-Andrew Lecoiu
22 replies
Twoisaprime
Feb 13, 2025
HoRI_DA_GRe8
an hour ago
Number theory field
slimshadyyy.3.60   2
N an hour ago by Primeniyazidayi
Prove that for every odd prime p there are infinitely many positive integers k such that the exponents
of 2 and k in the prime factorization of k! are even.
2 replies
slimshadyyy.3.60
Yesterday at 9:06 AM
Primeniyazidayi
an hour ago
sum(ab/4a^2+b^2) <= 3/5
truongphatt2668   1
N an hour ago by truongphatt2668
Source: I remember I read it somewhere
Let $a,b,c>0$. Prove that:
$$\dfrac{ab}{a^2+4b^2} + \dfrac{bc}{b^2+4c^2} + \dfrac{ca}{c^2+4a^2} \le \dfrac{3}{5}$$
1 reply
truongphatt2668
an hour ago
truongphatt2668
an hour ago
Jury Meeting Lasting for Twenty Years
USJL   4
N an hour ago by zRevenant
Source: 2025 Taiwan TST Round 2 Independent Study 1-C
2025 IMO leaders are discussing $100$ problems in a meeting. For each $i = 1, 2,\ldots , 100$, each leader will talk about the $i$-th problem for $i$-th minutes. The chair can assign one leader to talk about a problem of his choice, but he would have to wait for the leader to complete the entire talk of that problem before assigning the next leader and problem. The next leader can be the same leader. The next problem can be a different problem. Each leader’s longest idle time is the longest consecutive time that he is not talking.
Find the minimum positive integer $T$ so that the chair can ensure that the longest idle time for any leader does not exceed $T$.

Proposed by usjl
4 replies
USJL
Mar 26, 2025
zRevenant
an hour ago
Grasshoppers facing in four directions
Stuttgarden   1
N an hour ago by starchan
Source: Spain MO 2025 P5
Let $S$ be a finite set of cells in a square grid. On each cell of $S$ we place a grasshopper. Each grasshopper can face up, down, left or right. A grasshopper arrangement is Asturian if, when each grasshopper moves one cell forward in the direction in which it faces, each cell of $S$ still contains one grasshopper.
[list]
[*] Prove that, for every set $S$, the number of Asturian arrangements is a perfect square.
[*] Compute the number of Asturian arrangements if $S$ is the following set:
1 reply
Stuttgarden
2 hours ago
starchan
an hour ago
Inspired by old results
sqing   0
an hour ago
Source: Own
Let $ a,b,c> 0 $ and $ abc=1 $. Prove that
$$\frac1{a^2+a+k}+\frac1{b^2+b+k}+\frac1{c^2+c+k}\geq \frac{3}{k+2}$$Where $ 0<k \leq 1.$
0 replies
sqing
an hour ago
0 replies
Rearrange numbers such a sum in all 1 \times 3 rectangles doesn't change
NO_SQUARES   1
N an hour ago by Bardia7003
Source: Saint Petersburg olympiad 2024, 11.1
The $100 \times 100$ table is filled with numbers from $1$ to $10 \ 000$ as shown in the figure. Is it possible to rearrange some numbers so that there is still one number in each cell, and so that the sum of the numbers does not change in all rectangles of three cells?
1 reply
NO_SQUARES
Sep 22, 2024
Bardia7003
an hour ago
Something Horrible-a Challenge
Xueshuxue   23
N an hour ago by Demetri
Hello, I was wondering if it's possible to make 8 with the numbers 5, 3, 5, and 7 under the following rules:
-You can only use 5 twice, 3 once, and 7 once.
-You must use all the numbers.
You can stack numbers to form larger numbers (example: I could take 3 and 5 and turn it into 35 or 53, or use 7, 3, and 5 to make 375.)
-You are allowed to use parentheses.
(Also, I already found out that no 3 digital numbers will work for the solution.)
23 replies
Xueshuxue
Mar 28, 2025
Demetri
an hour ago
exponents
Arvind_sn   39
N 5 hours ago by ohiorizzler1434
What is the highest possible $e$ in $2^{e}<200$?
39 replies
Arvind_sn
Jul 12, 2006
ohiorizzler1434
5 hours ago
Water Watermelon
hwenterprise   23
N 5 hours ago by KF329
A giant watermelon weighed 50 pounds and was 99 percent water. After sitting in the hot sun, some of the water evaporated so that the watermelon was only 98 percent water. What is the new weight of the watermelon?
23 replies
hwenterprise
Sep 18, 2005
KF329
5 hours ago
Bogus Proof Marathon
pifinity   7536
N Today at 2:53 AM by vincentwant
Hi!
I'd like to introduce the Bogus Proof Marathon.

In this marathon, simply post a bogus proof that is middle-school level and the next person will find the error. You don't have to post the real solution :P

Use classic Marathon format:
[hide=P#]a1b2c3[/hide]
[hide=S#]a1b2c3[/hide]


Example posts:

P(x)
-----
S(x)
P(x+1)
-----
Let's go!! Just don't make it too hard!
7536 replies
pifinity
Mar 12, 2018
vincentwant
Today at 2:53 AM
Bogus Proof Marathon
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G H BBookmark kLocked kLocked NReply
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mithu542
1564 posts
#8070
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P1953
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happyfish0922
232 posts
#8071
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S1953
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RoyalPrince
170 posts
#8072
Y by
$\frac{1}{2}*\frac{2}{3}*\frac{5}{6}/\frac{1}{2}$=$\frac{5}{36}$
This post has been edited 3 times. Last edited by RoyalPrince, Mar 28, 2025, 2:49 PM
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Beaniebo4
51 posts
#8073
Y by
$                           $
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fruitmonster97
2417 posts
#8074
Y by
Beaniebo4 wrote:
Wait, that's not incorrect, is it?
$\tfrac12\cdot\tfrac23\cdot\tfrac{\tfrac56}{\tfrac12}=\tfrac{5}{9}.$
Z K Y
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Beaniebo4
51 posts
#8075
Y by
p1955
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fruitmonster97
2417 posts
#8076 • 1 Y
Y by dodidoes
Beaniebo4 wrote:
p1955

Well the last statement just says that "The number that you multiply by $0$ to get $1$ is undefined", which isn't exactly incorrect. imo it's a pretty gray area, but i'll roll with it.
S1955
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happyfish0922
232 posts
#8078
Y by
Coolmanppap3 wrote:
P1956

????? Whaaaa
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AVY2024
16 posts
#8079
Y by
What is p1956
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happyfish0922
232 posts
#8080
Y by
AVY2024 wrote:
What is p1956

Oh it just got removed
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Leeoz
159 posts
#8081
Y by
P1957
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Inaaya
209 posts
#8082
Y by
S1957
This post has been edited 2 times. Last edited by Inaaya, Yesterday at 12:31 AM
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Nick_Yang
4508 posts
#8084
Y by
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yaxuan
3312 posts
#8085
Y by
S1958?
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vincentwant
1279 posts
#8086
Y by
S1958
Z K Y
N Quick Reply
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