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Base 2n of n^k
KevinYang2.71   50
N Today at 1:39 AM by ray66
Source: USAMO 2025/1, USAJMO 2025/2
Let $k$ and $d$ be positive integers. Prove that there exists a positive integer $N$ such that for every odd integer $n>N$, the digits in the base-$2n$ representation of $n^k$ are all greater than $d$.
50 replies
KevinYang2.71
Mar 20, 2025
ray66
Today at 1:39 AM
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[CASH PRIZES] IndyINTEGIRLS Spring Math Competition
Indy_Integirls   55
N Today at 1:28 AM by GallopingUnicorn45
[center]IMAGE

Greetings, AoPS! IndyINTEGIRLS will be hosting a virtual math competition on May 25,
2024 from 12 PM to 3 PM EST. Join other woman-identifying and/or non-binary "STEMinists" in solving problems, socializing, playing games, winning prizes, and more! If you are interested in competing, please register here![/center]

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[center]Important Information[/center]

Eligibility: This competition is open to all woman-identifying and non-binary students in middle and high school. Non-Indiana residents and international students are welcome as well!

Format: There will be a middle school and high school division. In each separate division, there will be an individual round and a team round, where students are grouped into teams of 3-4 and collaboratively solve a set of difficult problems. There will also be a buzzer/countdown/Kahoot-style round, where students from both divisions are grouped together to compete in a MATHCOUNTS-style countdown round! There will be prizes for the top competitors in each division.

Problem Difficulty: Our amazing team of problem writers is working hard to ensure that there will be problems for problem-solvers of all levels! The middle school problems will range from MATHCOUNTS school round to AMC 10 level, while the high school problems will be for more advanced problem-solvers. The team round problems will cover various difficulty levels and are meant to be more difficult, while the countdown/buzzer/Kahoot round questions will be similar to MATHCOUNTS state to MATHCOUNTS Nationals countdown round in difficulty.

Platform: This contest will be held virtually through Zoom. All competitors are required to have their cameras turned on at all times unless they have a reason for otherwise. Proctors and volunteers will be monitoring students at all times to prevent cheating and to create a fair environment for all students.

Prizes: At this moment, prizes are TBD, and more information will be provided and attached to this post as the competition date approaches. Rest assured, IndyINTEGIRLS has historically given out very generous cash prizes, and we intend on maintaining this generosity into our Spring Competition.

Contact & Connect With Us: Email us at indy@integirls.org.

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[center]Help Us Out

Please help us in sharing the news of this competition! Our amazing team of officers has worked very hard to provide this educational opportunity to as many students as possible, and we would appreciate it if you could help us spread the word!
55 replies
Indy_Integirls
May 11, 2025
GallopingUnicorn45
Today at 1:28 AM
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How Math WOOT Level 2 prepare you for olympiad contest
AMC10JA   0
Yesterday at 11:35 PM
I know how you do on Olympiad is based on your effort and your thinking skill, but I am just curious is WOOT level 2 is generally for practicing the beginner olympiad contest (like USAJMO or lower), or also good to learn for hard olympiad contest (like USAMO and IMO).
Please share your thought and experience. Thank you!
0 replies
AMC10JA
Yesterday at 11:35 PM
0 replies
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Equilateral triangle $ABC$, $DEF$ has twice the area
v_Enhance   122
N Yesterday at 10:37 PM by lpieleanu
Source: JMO 2017 Problem 3, Titu, Luis, Cosmin
Let $ABC$ be an equilateral triangle, and point $P$ on its circumcircle. Let $PA$ and $BC$ intersect at $D$, $PB$ and $AC$ intersect at $E$, and $PC$ and $AB$ intersect at $F$. Prove that the area of $\triangle DEF$ is twice the area of $\triangle ABC$.

Proposed by Titu Andreescu, Luis Gonzales, Cosmin Pohoata
122 replies
v_Enhance
Apr 19, 2017
lpieleanu
Yesterday at 10:37 PM
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Perfect Square Dice
asp211   67
N Yesterday at 9:27 PM by A7456321
Source: 2019 AIME II #4
A standard six-sided fair die is rolled four times. The probability that the product of all four numbers rolled is a perfect square is $\tfrac{m}{n}$, where $m$ and $n$ are relatively prime positive integers. Find $m+n$.
67 replies
asp211
Mar 22, 2019
A7456321
Yesterday at 9:27 PM
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HCSSiM results
SurvivingInEnglish   75
N Yesterday at 7:25 PM by cowstalker
Anyone already got results for HCSSiM? Are there any point in sending additional work if I applied on March 19?
75 replies
SurvivingInEnglish
Apr 5, 2024
cowstalker
Yesterday at 7:25 PM
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Perfect squares: 2011 USAJMO #1
v_Enhance   227
N Yesterday at 7:23 PM by ray66
Find, with proof, all positive integers $n$ for which $2^n + 12^n + 2011^n$ is a perfect square.
227 replies
v_Enhance
Apr 28, 2011
ray66
Yesterday at 7:23 PM
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Mustang Math Recruitment is Open!
MustangMathTournament   0
Yesterday at 7:02 PM
The Interest Form for joining Mustang Math is open!

Hello all!

We're Mustang Math, and we are currently recruiting for the 2025-2026 year! If you are a high school or college student and are passionate about promoting an interest in competition math to younger students, you should strongly consider filling out the following form: https://link.mustangmath.com/join. Every member in MM truly has the potential to make a huge impact, no matter your experience!

About Mustang Math

Mustang Math is a nonprofit organization of high school and college volunteers that is dedicated to providing middle schoolers access to challenging, interesting, fun, and collaborative math competitions and resources. Having reached over 4000 U.S. competitors and 1150 international competitors in our first six years, we are excited to expand our team to offer our events to even more mathematically inclined students.

PROJECTS
We have worked on various math-related projects. Our annual team math competition, Mustang Math Tournament (MMT) recently ran. We hosted 8 in-person competitions based in Washington, NorCal, SoCal, Illinois, Georgia, Massachusetts, Nevada and New Jersey, as well as an online competition run nationally. In total, we had almost 900 competitors, and the students had glowing reviews of the event. MMT International will once again be running later in August, and with it, we anticipate our contest to reach over a thousand students.

In our classes, we teach students math in fun and engaging math lessons and help them discover the beauty of mathematics. Our aspiring tech team is working on a variety of unique projects like our website and custom test platform. We also have a newsletter, which, combined with our social media presence, helps to keep the mathematics community engaged with cool puzzles, tidbits, and information about the math world! Our design team ensures all our merch and material is aesthetically pleasing.

Some highlights of this past year include 1000+ students in our classes, AMC10 mock with 150+ participants, our monthly newsletter to a subscriber base of 6000+, creating 8 designs for 800 pieces of physical merchandise, as well as improving our custom website (mustangmath.com, 20k visits) and test-taking platform (comp.mt, 6500+ users).

Why Join Mustang Math?

As a non-profit organization on the rise, there are numerous opportunities for volunteers to share ideas and suggest projects that they are interested in. Through our organizational structure, members who are committed have the opportunity to become a part of the leadership team. Overall, working in the Mustang Math team is both a fun and fulfilling experience where volunteers are able to pursue their passion all while learning how to take initiative and work with peers. We welcome everyone interested in joining!

More Information

To learn more, visit https://link.mustangmath.com/RecruitmentInfo. If you have any questions or concerns, please email us at contact@mustangmath.com.

https://link.mustangmath.com/join
0 replies
MustangMathTournament
Yesterday at 7:02 PM
0 replies
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Moving P(o)in(t)s
bobthegod78   71
N Yesterday at 6:25 PM by ray66
Source: USAJMO 2021/4
Carina has three pins, labeled $A, B$, and $C$, respectively, located at the origin of the coordinate plane. In a move, Carina may move a pin to an adjacent lattice point at distance $1$ away. What is the least number of moves that Carina can make in order for triangle $ABC$ to have area 2021?

(A lattice point is a point $(x, y)$ in the coordinate plane where $x$ and $y$ are both integers, not necessarily positive.)
71 replies
bobthegod78
Apr 15, 2021
ray66
Yesterday at 6:25 PM
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Jane street swag package? USA(J)MO
arfekete   45
N Yesterday at 4:58 PM by vsarg
Hey! People are starting to get their swag packages from Jane Street for qualifying for USA(J)MO, and after some initial discussion on what we got, people are getting different things. Out of curiosity, I was wondering how they decide who gets what.
Please enter the following info:

- USAMO or USAJMO
- Grade
- Score
- Award/Medal/HM
- MOP (yes or no, if yes then color)
- List of items you got in your package

I will reply with my info as an example.
45 replies
arfekete
May 7, 2025
vsarg
Yesterday at 4:58 PM
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Graph of polynomials
Ecrin_eren   1
N Apr 20, 2025 by vanstraelen
The graph of the quadratic polynomial with real coefficients y = px^2 + qx + r, called G1, intersects the graph of the polynomial y = x^2, called G2, at points A and B. The lines tangent to G2 at points A and B intersect at point C. It is known that point C lies on G1. What is the value of p?
1 reply
Ecrin_eren
Apr 20, 2025
vanstraelen
Apr 20, 2025
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Graph of polynomials
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Ecrin_eren
104 posts
Ecrin_eren
#1 h  Apr 20, 2025, 3:00 PM
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The graph of the quadratic polynomial with real coefficients y = px^2 + qx + r, called G1, intersects the graph of the polynomial y = x^2, called G2, at points A and B. The lines tangent to G2 at points A and B intersect at point C. It is known that point C lies on G1. What is the value of p?
This post has been edited 1 time. Last edited by Ecrin_eren, Apr 20, 2025, 8:30 PM
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vanstraelen
9061 posts
vanstraelen
#2 h  Apr 20, 2025, 5:36 PM
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Given the parabola $G_{2}:y=x^{2}$ and the points $A(\lambda,\lambda^{2}),B(\mu,\mu^{2})$.
The tangent lines $y=2\lambda x-\lambda^{2}$ and $y=2\mu x-\mu^{2}$ intersect in the point $C(\frac{\lambda+\mu}{2},\lambda \mu)$.

The three points $A,B,C$ lie on $G_{1}:y=px^{2}+qx+r$, giving a system of three equations with three unknowns.
Solving: $p=2,q=-\lambda-\mu,r=\lambda \mu$.
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