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k a May Highlights and 2025 AoPS Online Class Information
jlacosta   0
Yesterday at 11:16 PM
May is an exciting month! National MATHCOUNTS is the second week of May in Washington D.C. and our Founder, Richard Rusczyk will be presenting a seminar, Preparing Strong Math Students for College and Careers, on May 11th.

Are you interested in working towards MATHCOUNTS and don’t know where to start? We have you covered! If you have taken Prealgebra, then you are ready for MATHCOUNTS/AMC 8 Basics. Already aiming for State or National MATHCOUNTS and harder AMC 8 problems? Then our MATHCOUNTS/AMC 8 Advanced course is for you.

Summer camps are starting next 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 an enriching 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][*]May 9th, 4:30pm PT/7:30pm ET, Casework 2: Overwhelming Evidence — A Text Adventure, a game where participants will work together to navigate the map, solve puzzles, and win! All are welcome.
[*]May 19th, 4:30pm PT/7:30pm ET, What's Next After Beast Academy?, designed for students finishing Beast Academy and ready for Prealgebra 1.
[*]May 20th, 4:00pm PT/7:00pm ET, Mathcamp 2025 Qualifying Quiz Part 1 Math Jam, Problems 1 to 4, join the Canada/USA Mathcamp staff for this exciting Math Jam, where they discuss solutions to Problems 1 to 4 of the 2025 Mathcamp Qualifying Quiz!
[*]May 21st, 4:00pm PT/7:00pm ET, Mathcamp 2025 Qualifying Quiz Part 2 Math Jam, Problems 5 and 6, Canada/USA Mathcamp staff will discuss solutions to Problems 5 and 6 of the 2025 Mathcamp Qualifying Quiz![/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
Yesterday at 11:16 PM
0 replies
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extremaly hard NT
gggzul   0
24 minutes ago
Source: Cambodian IMO training camp
We will say that a set of $2025$ consecutive positive integers is cool if it contains exactly $13$ primes. Are there infinitely many cool sets?
0 replies
+1 w
gggzul
24 minutes ago
0 replies
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3 var inequality
sqing   1
N 26 minutes ago by pooh123
Source: Own
Let $ a,b,c>0 ,\frac{a}{b} +\frac{b}{c} +\frac{c}{a} \leq 2\left( \frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right). $ Prove that
$$a+b+c+2\geq abc$$Let $ a,b,c>0 , a^3+b^3+c^3\leq 2(ab+bc+ca). $ Prove that
$$a+b+c+2\geq abc$$
1 reply
sqing
Wednesday at 9:30 AM
pooh123
26 minutes ago
J
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Tangent to two circles
Mamadi   0
32 minutes ago
Source: Own
Two circles \( w_1 \) and \( w_2 \) intersect each other at \( M \) and \( N \). The common tangent to two circles nearer to \( M \) touch \( w_1 \) and \( w_2 \) at \( A \) and \( B \) respectively. Let \( C \) and \( D \) be the reflection of \( A \) and \( B \) respectively with respect to \( M \). The circumcircle of the triangle \( DCM \) intersect circles \( w_1 \) and \( w_2 \) respectively at points \( E \) and \( F \) (both distinct from \( M \)). Show that the line \( EF \) is the second tangent to \( w_1 \) and \( w_2 \).
0 replies
Mamadi
32 minutes ago
0 replies
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Number Theory problem
Mamadi   0
34 minutes ago
Source: Own
Find all \( a, b \in \mathbb{N} \) such that \( a! + b \) and \( b! + a \) are both perfect squares.
0 replies
Mamadi
34 minutes ago
0 replies
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How You Know You Understand a New Programming Language
rrusczyk   4
N Feb 18, 2011 by joshim5
Your debugging time is spent more on logic issues than on syntax.
4 replies
rrusczyk
Feb 5, 2011
joshim5
Feb 18, 2011
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Installing Python
rrusczyk   5
N Aug 26, 2010 by blabla4198
We are offering an Introduction to Programming course for the first time this fall. We have put together instructions for installing Python, the language we will use in the course, on your computer. Here are the instructions. Please give these instructions a try, and attempt to install the program yourself. When you're finished, please comment here about the instructions (include your operating system).

Thanks!
5 replies
rrusczyk
Aug 19, 2010
blabla4198
Aug 26, 2010
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Programming Classes at AoPS
rrusczyk   0
Jul 1, 2010
Our first computer science/programming class is now available. Details here.
0 replies
rrusczyk
Jul 1, 2010
0 replies
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AoPS Expanding to Programming & CS
rrusczyk   11
N Mar 24, 2010 by rrusczyk
We are going to investigate building courses in programming and computer science. We'll likely start with courses for students with little or no programming experience, and expand from there. If any of you have thoughts on what you'd like to see, or what programming/CS courses have or haven't worked for you, please let us know!
11 replies
rrusczyk
Mar 22, 2010
rrusczyk
Mar 24, 2010
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Want to Learn Java
rrusczyk   0
Jan 16, 2010
Dan Zaharopol connected me with a friend of his who is creating a new tool to learn programming in Java. You can find it here. I played with it a little bit, and while it's clearly in its early stages, I found it very appealing. If you have a chance to use it for a while, please post your comments on it here, or email them to me, so I can give feedback to the creator of the program as he continues to develop it.

(One thing I noted is that, at least for the early lessons, you have to do way too many basic exercises to move past them. Fortunately, there's a cheat to jump past early stuff once you understand it: just shift-click on modules to open them :) )
0 replies
rrusczyk
Jan 16, 2010
0 replies
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Kodu
rrusczyk   4
N Jul 12, 2009 by rrusczyk
This is a new game to learn programming from Microsoft. Has anyone used it? Is it any good?
4 replies
rrusczyk
Jul 11, 2009
rrusczyk
Jul 12, 2009
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Programming
rrusczyk   18
N Feb 8, 2009 by Paiev
If you learned how to program in the last 5-10 years, how did you learn how to code? Specifically, how did you get started -- did you take a class? Have mom, dad, brother, or sister install something for you? Poke around on the internet to figure out how? (And if so, where?)

Back when I was a kid, it was easy to start -- turn on your computer, and away you go. Nothing to install. No fancy programs to figure out. Just turn on the computer and start hacking away. Now, it's much harder to take that first step if you don't have someone to show you how. I think this is a big part of why my generation (roughly) was much more likely to code than subsequent generations. Windows and the Mac have made nearly everything better than it was under DOS and Apple II, but not getting started with programming. I hope some day to make headway in changing that in a small degree by building something at AoPS that will help this, but I think that may be a ways off. In the meantime, I'd like to learn about how students start programming now.
18 replies
rrusczyk
Jan 19, 2009
Paiev
Feb 8, 2009
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No more topics!
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Counting graph theory
MathSaiyan   1
N Apr 30, 2025 by biomathematics
Source: PErA 2025/6
Let $m$ and $n$ be positive integers. For a connected simple graph $G$ on $n$ vertices and $m$ edges, we consider the number $N(G)$ of orientations of (all of) its edges so that, in the resulting directed graph, every vertex has even outdegree.
Show that $N(G)$ only depends on $m$ and $n$, and determine its value.
1 reply
MathSaiyan
Mar 17, 2025
biomathematics
Apr 30, 2025
J
Counting graph theory
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Reveal topic tags
graph theory
combinatorics
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G H BBookmark kLocked kLocked NReply
Source: PErA 2025/6
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MathSaiyan
75 posts
MathSaiyan
#1 h  Mar 17, 2025, 2:00 PM
Y by
Let $m$ and $n$ be positive integers. For a connected simple graph $G$ on $n$ vertices and $m$ edges, we consider the number $N(G)$ of orientations of (all of) its edges so that, in the resulting directed graph, every vertex has even outdegree.
Show that $N(G)$ only depends on $m$ and $n$, and determine its value.
Z K Y
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
biomathematics
2568 posts
biomathematics
#2 h  Apr 30, 2025, 2:28 AM
Y by
I believe $N(G) = 2^{m-n+1}$. Take a spanning tree of $G$. Orient all other edges arbitrarily, and the orientation of the tree is uniquely determined.
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