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k a April Highlights and 2025 AoPS Online Class Information
jlacosta   0
Apr 2, 2025
Spring is in full swing and summer is right around the corner, what are your plans? At AoPS Online our schedule has new classes starting now through July, so be sure to keep your skills sharp and be prepared for the Fall school year! Check out the schedule of upcoming classes below.

WOOT early bird pricing is in effect, don’t miss out! If you took MathWOOT Level 2 last year, no worries, it is all new problems this year! Our Worldwide Online Olympiad Training program is for high school level competitors. AoPS designed these courses to help our top students get the deep focus they need to succeed in their specific competition goals. Check out the details at this link for all our WOOT programs in math, computer science, chemistry, and physics.

Looking for summer camps in math and language arts? Be sure to check out the video-based summer camps offered at the Virtual Campus that are 2- to 4-weeks in duration. 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 events:
[list][*]April 3rd (Webinar), 4pm PT/7:00pm ET, Learning with AoPS: Perspectives from a Parent, Math Camp Instructor, and University Professor
[*]April 8th (Math Jam), 4:30pm PT/7:30pm ET, 2025 MATHCOUNTS State Discussion
April 9th (Webinar), 4:00pm PT/7:00pm ET, Learn about Video-based Summer Camps at the Virtual Campus
[*]April 10th (Math Jam), 4:30pm PT/7:30pm ET, 2025 MathILy and MathILy-Er Math Jam: Multibackwards Numbers
[*]April 22nd (Webinar), 4:00pm PT/7:00pm ET, Competitive Programming at AoPS (USACO).[/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
Apr 2, 2025
0 replies
1234th Post!
PikaPika999   145
N an hour ago by Soupboy0
I hit my 1234th post! (I think I missed it, I'm kinda late, :oops_sign:)

But here's a puzzle for you all! Try to create the numbers 1 through 25 using the numbers 1, 2, 3, and 4! You are only allowed to use addition, subtraction, multiplication, division, and parenthesis. If you're post #1, try to make 1. If you're post #2, try to make 2. If you're post #3, try to make 3, and so on. If you're a post after 25, then I guess you can try to make numbers greater than 25 but you can use factorials, square roots, and that stuff. Have fun!

1: $(4-3)\cdot(2-1)$
145 replies
PikaPika999
Yesterday at 8:54 PM
Soupboy0
an hour ago
Bogus Proof Marathon
pifinity   7610
N an hour ago by iwastedmyusername
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!
7610 replies
pifinity
Mar 12, 2018
iwastedmyusername
an hour ago
bracelets
pythagorazz   7
N an hour ago by H1u2g4o4
Kat designs circular bead bracelets for kids. Each bracelet has 5 beads, all of which are either yellow or green. If beads of the same color are identical, how many distinct bracelets could Kat make?
7 replies
pythagorazz
Apr 14, 2025
H1u2g4o4
an hour ago
Website to learn math
hawa   40
N 2 hours ago by K1mchi_
Hi, I'm kinda curious what website do yall use to learn math, like i dont find any website thats fun to learn math
40 replies
hawa
Apr 9, 2025
K1mchi_
2 hours ago
No more topics!
The daily problem!
Leeoz   117
N Apr 20, 2025 by aidan0626
Every day, I will try to post a new problem for you all to solve! If you want to post a daily problem, you can! :)

Please hide solutions and answers, hints are fine though! :)

Problems usually get harder throughout the week, so Sunday is the easiest and Saturday is the hardest!

Past Problems!
117 replies
Leeoz
Mar 21, 2025
aidan0626
Apr 20, 2025
The daily problem!
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pieMax2713
4179 posts
#108
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sol
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HacheB2031
379 posts
#109
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April 13th Problem wrote:
If today is a Sunday, what day of the week will it be in 123 days, not including today?

ez sol
This post has been edited 1 time. Last edited by HacheB2031, Apr 14, 2025, 2:51 PM
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HacheB2031
379 posts
#110
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me when sombody says
HacheB2031 wrote:
HacheB2031 wrote:
new problem por favor :maybe:

yeah what he said :huh:
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Leeoz
176 posts
#111
Y by
HacheB2031 wrote:
me when sombody says
HacheB2031 wrote:
HacheB2031 wrote:
new problem por favor :maybe:

yeah what he said :huh:

:oops_sign:
...

April 13th Answer

April 15th Problem wrote:
A lottery has a $\$50,000,000$ jackpot! However, a ticket costs $\$1$. You get 4 random positive integers that are at most 100, and if they are match the 4 random lottery numbers (in order) you win the jackpot! Find the expected loss for a lottery ticket.
This post has been edited 1 time. Last edited by Leeoz, Apr 16, 2025, 4:45 AM
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iwastedmyusername
111 posts
#112
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AbhayAttarde01
1484 posts
#113
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sol apr15
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That_One_Genius.
6 posts
#114
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Solution:Click to reveal hidden text
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Leeoz
176 posts
#115
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April 15th Answer

April 18th Problem wrote:
If the probability that there is a daily problem is 50%, what is the probability that after 1 week, there was exactly 6 daily problems?
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sadas123
1231 posts
#116
Y by
April 18th Solution
This post has been edited 1 time. Last edited by sadas123, Apr 18, 2025, 7:37 PM
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huajun78
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#117
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valenbb
663 posts
#118
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sol 4/18
This post has been edited 4 times. Last edited by valenbb, Apr 19, 2025, 1:05 AM
Reason: sdwasfrgtb
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HacheB2031
379 posts
#120
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April 18th Problem wrote:
If the probability that there is a daily problem is 50%, what is the probability that after 1 week, there was exactly 6 daily problems?

exactly what leeoz does every week
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Leeoz
176 posts
#121
Y by
April 18th Answer

April 19th Problem wrote:
What is the value of the infinite sum $\frac{1}{2^1}+\frac{2}{2^2}+\frac{3}{2^3}+...$?
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mikkymini2
13 posts
#122 • 1 Y
Y by aidan0626
April 19th Problem wrote:
What is the value of the infinite sum $\frac{1}{2^1}+\frac{2}{2^2}+\frac{3}{2^3}+...$?
[/quote]

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aidan0626
1855 posts
#123
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personal feed
leeoz you should update the op with all the new problems
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