stat moment pt 2

by fruitmonster97, Apr 17, 2025, 4:38 PM

There exists a list of $n$ positive integers with mean, median, mode, and range equal to positive real $x.$ Compute the minimum possible value of $n.$

easy olympiad problem

by kjhgyuio, Apr 17, 2025, 2:00 PM

Find all positive integer values of $x$ such that
$\sqrt{x - 2011} + \sqrt{2011 - x} + 10$ is an integer.

This post has been edited 2 times. Last edited by kjhgyuio, Yesterday at 2:01 PM
Reason: nil

Olympiad

2500th post

by Solocraftsolo, Apr 16, 2025, 3:09 PM

i keep forgetting to do these...

2500 is cool.

i am not very sentimental so im not going to post a math story or anything.

here are some problems though

p1p2p3

p4

This post has been edited 5 times. Last edited by Solocraftsolo, Wednesday at 3:40 PM

probability

expected value

many posts

1000th Post!

by PikaPika999, Apr 5, 2025, 11:32 PM

When I had less than 25 posts on AoPS, I saw many people create threads about them getting 1000th posts. I thought I would never hit 1000 posts, but here we are, this is my 1000th post.

As a lot of users like to do, I'll write my math story:

Daycare
Preschool
Kindergarten
First Grade
Second Grade
Third Grade
Fourth Grade
Fifth Grade
Sixth Grade
Quick Quote that was from MLK that I edited

In conclusion, AoPS has helped me improve my math. I have also made many new friends on AoPS!

Finally, I would like to say thank you to all the new friends I made and all the instructors on AoPS that taught me!

Minor side note, but

This post has been edited 1 time. Last edited by PikaPika999, 6 hours ago

divisible by 111

by aria123, Apr 1, 2025, 3:16 PM

How many 6-digit natural numbers (with distinct digits) can be formed using the digits 2, 3, 4, 5, 6, and 7 that are divisible by 111?

number theory

I think I regressed at math

by PaperMath, Mar 8, 2025, 4:10 AM

I found the slip of paper a few days ago that I think I wrote when I was in kindergarten. It is just a sequence of numbers and you have to find the next number, the pattern is $1,2,5,40,1280,?$ . I couldn't solve this and was wondering if any of you can find the pattern

Is there a point in me continuing AoPS?

by julll55, Feb 24, 2025, 1:28 AM

Okay so for context, I am in 8th grade and I'm bad at math, well at least on the competitive level like AMC and stuff. When I was in 7th grade I did some practice AMC8 tests and got like 15-17.

I've just been recently wondering if there is a point in me continuing AoPS. It's not like I'm ever really going to be competitive at math at this rate, and I can't exactly devote more time to it because I have too many other activities I have to do. And since I'm going into 9th grade next year, I have to start taking the AMC10 to be able to go into further math competitions like the AIME. Plus, my school system doesn't do anything related to a math team (I live in Alabama).

So I'm not sure if I should continue learning math from AoPS, because I feel like I could just devote the 12-15 hours I spend on math each week to something else that I am actually good at. The only thing that is sort of stopping me is how much I've already invested into AoPS. I've done Beast Academy, pre-algebra through int algebra. intro c&p, into geo, intro number theory, amc8 and mathcounts.

To be honest, I just don't think I'm talented or even wanting to spend like 20+ hours a week on math just to be able to qualify for these types of competitions. I know that it can be good as an extracurricular and all, but I don't know if it's worth it to grind math. Because in school I do fine, I have like 100 in math, so it's not like I need extra tutoring.

ENTER YOUR CHAPTER INVITATIONAL SCORE

by ihatemath123, Feb 27, 2021, 7:23 PM

I'll start:
$\begin{tabular}{|c|c|c|c|c|}Username&Grade&Sprint&Target&TOTAL \\ \hline ihatemath123&7&26&6&38 \\ \hline \end{tabular}$

chapter invitational

MATHCOUNTS

Annoying Probability Math Problem

by RYang2, Mar 14, 2018, 5:07 PM

I was working in my math textbook(not the AoPS one) when I came across this math problem:

Determine if the events are dependent or independent.
1. Drawing a red and a blue marble at the same time from a bag containing 6 red and 4 blue marbles
2.(omitted)

I thought it was independent, since the events happen at the same time, but the textbook answer said dependent.
Can someone help me understand(or prove the textbook wrong)?

This post has been edited 1 time. Last edited by RYang2, Mar 14, 2018, 5:10 PM
Reason: Too general subject

Math Problem

probability

Bogus Proof Marathon

by pifinity, Mar 12, 2018, 7:33 PM

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

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!

This post has been edited 3 times. Last edited by pifinity, Mar 12, 2018, 7:40 PM

bogus proof

marathon

Submit

dj so orz
by Yiyj1, Mar 29, 2025, 1:42 AM
legendary problem writer
by Clew28, Jul 29, 2024, 7:20 PM
orz $\,$
by balllightning37, Jul 26, 2024, 1:05 AM
hi dj $\text{[math]}$ $\text{[math]}$
by OronSH, Jul 23, 2024, 2:14 AM
i wanna submit my own problems lol
by ethanzhang1001, Jul 20, 2024, 9:54 PM
hi dj, may i have the role of contributer?
by lpieleanu, Feb 23, 2024, 1:31 AM
This was helpful!
by YIYI-JP, Nov 23, 2023, 12:42 PM
waiting for a recap of your amc proposals for this year
by ihatemath123, Feb 17, 2023, 3:18 PM
also happy late bday man! i missed it by 2 days but hope you are enjoyed it
by ab456, Dec 30, 2022, 10:58 AM
Contrib?
by MC413551, Nov 20, 2022, 10:48 PM
tfw kakuro appears on amc
by bissue, Aug 18, 2022, 4:32 PM
Hi dj
by 799786, Aug 10, 2022, 1:44 AM
Roses are red,
Wolfram is banned,
The best problem writer is
Djmathman
by ihatemath123, Aug 6, 2022, 12:19 AM
hello
by aidan0626, Jul 26, 2022, 5:49 PM
Do you have a link to your main blog that you started after graduating from high school, I couldn't find it. @dj I met you IRL at Awesome Math summer Program several years ago.
by First, Mar 1, 2022, 5:18 PM
how did you do that cursor
by mathgenius64, Sep 1, 2011, 10:14 PM
Finally posted that problem! And hooray for pencil cursor!
by djmathman, Aug 24, 2011, 6:49 PM
Geo 2 is correct though
by sjaelee, Aug 24, 2011, 12:21 AM
Hello...Lol yesterday sjaelee posted Geomretry #2. Isn't it supposed to be Geometry #2? Lol.
by mcqueen, Aug 23, 2011, 11:57 PM
Delete geo #4! Plese!
by sjaelee, Aug 22, 2011, 11:41 PM
Hrm, there's this problem that I've been too lazy to post. I think I should soon.
by djmathman, Aug 22, 2011, 7:02 PM
Why hello...funny I'm saying this when I know you'll be unresponsive because you're V/LA for a week.
by mcqueen, Aug 14, 2011, 10:47 AM
But that's because those problems are the easiest to find.
by djmathman, Aug 12, 2011, 3:49 AM
Yea, I kind of keep forgetting to change that.
by djmathman, Aug 11, 2011, 11:27 AM
I noticed that only algebra and number theory come up (trig was basically algebra)
by sjaelee, Aug 11, 2011, 11:22 AM
There you go.
by djmathman, Aug 7, 2011, 2:07 PM
*cough* contrib
by Mrdavid445, Aug 7, 2011, 12:40 PM
Ah, i'm sure you will use this blog well.
by tc1729, Aug 7, 2011, 2:10 AM
First shout!
by djmathman, Aug 5, 2011, 6:58 PM

363 shouts

Blog of the (Former) Rising Olympian