2014 amc 10 a problem 23

by Rook567, May 26, 2025, 7:31 PM

Why do solutions assume 30 60 90 triangles?
If you assume 45 45 90 you get 5/6 as answer, don’t you?

Mustang Math Recruitment is Open!

by MustangMathTournament, May 24, 2025, 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

Zsigmondy's theorem

by V0305, May 24, 2025, 6:22 PM

Is Zsigmondy's theorem allowed on the IMO, and is it allowed on the AMC series of proof competitions (e.g. USAJMO, USA TSTST)?

[TEST RELEASED] OMMC Year 5

by DottedCaculator, Apr 26, 2025, 5:40 PM

Test portal: https://ommc-test-portal-2025.vercel.app/

Hello to all creative problem solvers,

Do you want to work on a fun, untimed team math competition with amazing questions by MOPpers and IMO & EGMO medalists? $\phantom{You lost the game.}$
Do you want to have a chance to win thousands in cash and raffle prizes (no matter your skill level)?

Check out the fifth annual iteration of the

Online Monmouth Math Competition!

Online Monmouth Math Competition, or OMMC, is a 501c3 accredited nonprofit organization managed by adults, college students, and high schoolers which aims to give talented high school and middle school students an exciting way to develop their skills in mathematics.

Our website: https://www.ommcofficial.org/

This is not a local competition; any student 18 or younger anywhere in the world can attend. We have changed some elements of our contest format, so read carefully and thoroughly. Join our Discord or monitor this thread for updates and test releases.

How hard is it?

We plan to raffle out a TON of prizes over all competitors regardless of performance. So just submit: a few minutes of your time will give you a great chance to win amazing prizes!

How are the problems?

You can check out our past problems and sample problems here:
https://www.ommcofficial.org/sample
https://www.ommcofficial.org/2022-documents
https://www.ommcofficial.org/2023-documents
https://www.ommcofficial.org/ommc-amc

How will the test be held?/How do I sign up?

Solo teams?

Test Policy

Timeline:
Main Round: May 17th - May 24th
Test Portal Released. The Main Round of the contest is held. The Main Round consists of 25 questions that each have a numerical answer. Teams will have the entire time interval to work on the questions. They can submit any time during the interval. Teams are free to edit their submissions before the period ends, even after they submit.

Final Round: May 26th - May 28th
The top placing teams will qualify for this invitational round (5-10 questions). The final round consists of 5-10 proof questions. Teams again will have the entire time interval to work on these questions and can submit their proofs any time during this interval. Teams are free to edit their submissions before the period ends, even after they submit.

Conclusion of Competition: Early June
Solutions will be released, winners announced, and prizes sent out to winners.

Scoring:

Prizes:

I have more questions. Whom do I ask?

We hope for your participation, and good luck!

OMMC staff

OMMC’S 2025 EVENTS ARE SPONSORED BY:

  • Nontrivial Fellowship
  • Citadel
  • SPARC
  • Jane Street
  • And counting!
Attachments:
OMMC_2025_3.pdf (275kb)
This post has been edited 4 times. Last edited by AoPSSheriff, May 21, 2025, 6:34 PM
Reason: Removed social link.

Alcumus vs books

by UnbeatableJJ, Apr 23, 2025, 12:58 PM

If I am aiming for AIME, then JMO afterwards, is Alcumus adequate, or I still need to do the problems on AoPS books?

I got AMC 23 this year, and never took amc 10 before. If I master the alcumus of intermediate algebra (making all of the bars blue). How likely I can qualify for AIME 2026?
This post has been edited 1 time. Last edited by UnbeatableJJ, May 15, 2025, 2:32 AM

what the yap

by KevinYang2.71, Mar 20, 2025, 12:00 PM

Alice the architect and Bob the builder play a game. First, Alice chooses two points $P$ and $Q$ in the plane and a subset $\mathcal{S}$ of the plane, which are announced to Bob. Next, Bob marks infinitely many points in the plane, designating each a city. He may not place two cities within distance at most one unit of each other, and no three cities he places may be collinear. Finally, roads are constructed between the cities as follows: for each pair $A,\,B$ of cities, they are connected with a road along the line segment $AB$ if and only if the following condition holds:
For every city $C$ distinct from $A$ and $B$, there exists $R\in\mathcal{S}$ such
that $\triangle PQR$ is directly similar to either $\triangle ABC$ or $\triangle BAC$.
Alice wins the game if (i) the resulting roads allow for travel between any pair of cities via a finite sequence of roads and (ii) no two roads cross. Otherwise, Bob wins. Determine, with proof, which player has a winning strategy.

Note: $\triangle UVW$ is directly similar to $\triangle XYZ$ if there exists a sequence of rotations, translations, and dilations sending $U$ to $X$, $V$ to $Y$, and $W$ to $Z$.

Do you need to attend mop

by averageguy, Mar 5, 2025, 6:06 PM

So I got accepted into a summer program and already paid the fee of around $5000 dollars. It's for 8 weeks (my entire summer) and it's in person. I have a few questions
1. If I was to make MOP this year am I forced to attend?
2.If I don't attend the program but still qualify can I still put on my college application that I qualified for MOP or can you only put MOP qualifier if you actually attend the program.

Special Points on $BC$

by tenniskidperson3, May 1, 2013, 10:01 PM

Let $ABC$ be a triangle. Find all points $P$ on segment $BC$ satisfying the following property: If $X$ and $Y$ are the intersections of line $PA$ with the common external tangent lines of the circumcircles of triangles $PAB$ and $PAC$, then \[\left(\frac{PA}{XY}\right)^2+\frac{PB\cdot PC}{AB\cdot AC}=1.\]

USAJMO problem 3: Inequality

by BOGTRO, Apr 24, 2012, 9:57 PM

Inequality with a^2+b^2+c^2+abc=4

by cn2_71828182846, Jun 27, 2004, 5:54 PM

Let $a, b, c \geq 0$ and satisfy \[ a^2+b^2+c^2 +abc = 4 . \] Show that \[ 0 \le ab + bc + ca - abc \leq 2. \]
This post has been edited 1 time. Last edited by v_Enhance, May 11, 2014, 3:38 PM
Reason: Added left bound from original problem statement

It's not just good - it's revolutionary!

avatar

liberator
Shouts
Submit
  • whoa....

    by bachkieu, Jan 31, 2025, 1:40 AM

  • hello...

    by ethan2011, Jul 4, 2024, 5:13 PM

  • 2024 shout ftw

    by Shreyasharma, Feb 19, 2024, 10:28 PM

  • time flies

    by Asynchrone, Dec 13, 2023, 9:29 PM

  • first 2023 shout :D

    by gracemoon124, Aug 2, 2023, 4:58 AM

  • offline.................

    by 799786, Dec 27, 2021, 7:08 AM

  • YOU SHALL NOT PASS! - liberator

    by OlympusHero, Aug 16, 2021, 4:10 AM

  • Nice Blog!

    by geometry6, Jul 31, 2021, 1:39 PM

  • First shout out in 2021 :D

    by Aimingformygoal, May 31, 2021, 4:23 PM

  • indeed a pr0 blog :surf:

    by Kanep, Dec 3, 2020, 10:46 PM

  • pr0 blog !!

    by Hamroldt, Dec 2, 2020, 8:32 AM

  • niice bloog!

    by Eliot, Oct 1, 2020, 3:27 PM

  • nice blog :o

    by fukano_2, Aug 8, 2020, 7:49 AM

  • Nice blog :)

    by Feridimo, Mar 31, 2020, 9:29 AM

  • Very nice blog !

    by Kamran011, Oct 31, 2019, 5:48 PM

56 shouts
Tags
About Owner
  • Posts: 95
  • Joined: May 28, 2014
Blog Stats
  • Blog created: Aug 13, 2014
  • Total entries: 46
  • Total visits: 39087
  • Total comments: 43
Search Blog
a