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1. 2 @SciFiChess (2, 5) 2. 1 @Marco (0, 3) 2. 1 @cellomaster8 (1) 2. 1 @StupidPersonRomania (4) 5. 0

This contest will have problems posted on a forum on Aug 1 00:00 GMT time. This contest consists of 15 OLYMPIAD-LEVEL maths problems written by me, @LLLhk. Anyone can participate. The time limit is the first half of August! Submit your answers (no need working, but answers) via PM to me on or before Aug 15 23:59 GMT time. These problems are from easy to hard, and all answers are positive integers. You may consult any sources online and you do not need to refer to them when you submit. You may also use computer programs, calculators, and Geogebra(Geometry application). These problems are OLYMPIAD-LEVEL, as I said, so getting 5/15 would already be quite good. NO COLLABORATION ALLOWED (This means no consulting other people). I will grade the answers, and results will be out by Sep 1. YOU DO NOT NEED TO REGISTER. JUST REMEMBER TO SUBMIT THE ANSWERS. LATE SUBMISSIONS WILL NOT COUNT. Official Solutions and Answers will be out before Oct 1. @LLLhk

A random math problem for when you're bored I solved it in around 1 to 10 minutes

Grade School problem in China, but probably for most of you will be middle school xD: Pipe A can fill a pool in 2 hours, pipe B can fill it in 1 hour, if pipe C can fill it in x hours, and altogether the pool can be filled in 30 minutes, what is x?

Do anyone understand this? It's on Off Topic Forums chess.com, there's a remake of Neal.fun's password game. Then someone made this rule. Previously I got 80.8. The math problem is revised in screenshot 3

Let's name some YouTube channel about science and math (that are in English language) in here so that people know about it. I'll start: Chirag Dudhat  Cuemath Domain of Science evanthorizon  Fermilab Kurzgesagt - In a Nutshell  Kyle Hill Looking Glass Universe  MindYourDesicions  Mission Unstoppable  NileRed NileRed 2 NileBlue  Numberphile  Primer Science Channel  TAMU Physics and Astronomy  The Organic Chemistry Tutor  The Science Asylum  The Thought Emporium  This. Tibees Up and Atom Veritasium  Vsauce Vsauce2 Vsauce3  Tejas Hullur  Physics Girl AsapSCIENCE 

Please post jokes here

What are your favorite topics in each subject area and why? Share your thoughts below!

Today I reached my new best in Puzzle Rush Survival! A few weeks ago, I could only get <10. But, after doing a lot of puzzles, my puzzle rating is around 1200. I think 2 weeks ago I got 19 in puzzle rush survival, just 1 short @ChessSensasian's record, but spending a lot more time. @ChessSensasian has reached 20(i am very impressed that he got 20 in 3 min, 5 min, AND survival!), and today I have also in survival. Still, I spent WAY too much time (0:51 avg per puzzle). However, my goal today was to reach 20, so I did it slowly, and at the end I did it! I think the most fortunate moment was solving https://www.chess.com/puzzles/problem/496724, which is Rf8, threatening Qg8#. To prevent the mate, black will have to play Qf2+ giving up the queen, or play h5, but anyways the black queen is trapped. Share your best puzzle rushes below! P.S. Yes my background is the CCMSL background.

Who wants to go first?

Hey guys! There's this new video about what 0 divided by 0 actually equals, and it debunks a big misconception. It's actually a great explanation of 0/0, and I can't believe I didn't realize that almost every other explanation I found online was actually wrong. You guys should definitely check it out, and post what you guys think about it here on the notes. Here's the link: https://www.youtube.com/watch?v=gK_R4eOLPq0&t=5s

Taken with: Celestron Inspire 90 Az An interesting fact you may not have known about the moon: the darker areas are smooth lowlands called maria (composed of basalt) whereas the lighter areas are more rugged highlands called terrae (composed of conglomerate).

PLEASE NOTE THAT A LOT OF THESE ARE VERY CHALLENGING AND I MIGHT NOT ACHIEVE ALL OF THEM. THE BRACKETS INDICATE THE EXPECTED PROBABILITY OF ACHIEVING THEM. School: - Not get detention (50%) - Join the school chess club (99%) Done - Join school math club and then betray it by not joining the school math team when in international contests xD (99.99999999999999...%=100%) Done Math: - Get top 10 national in some high school math contest (DONE!!!) Done within 1 day of school???? On AMT our team got 1st in Power (highest ever score and most done by me), Team, and Guts. Indiv I only got top 25% but Daniel Siyuan Chen got 1st place sole, and we broke a few records. - Get >240 USAMO index (10%) Physics: - Get higher than average in Physicsbowl (50%) Youtube Channel: - Get over 100 subs (50%) Done a long time ago Chess.com clubs: - Expand CCMSL and LoC to over 300 and 400 members respectively (50% and 75%, respectively) Nope not at all no hope - Continue to be the owner in the clubs I mentioned (50% AND YES! I MIGHT CLOSE MY ACCOUNT IN THE SCHOOL YEAR, AND IN THE CASE I DO, I WILL HAND MY CLUBS OVER TO... Hashi, or @Hyper_Speed20, or ananthramdas, or ... someone that will be known in the future) Personal stuff: - Done

first puzzle: gbi gnab

The diagram shows one way in which a 3 × 10 rectangle can be tiled by 15 rectangles of size 1×2.Since this tiling has no symmetry, we count rotations and reflections of this tiling as different tilings. How many different tilings of this 3 × 10 rectangle are possible?

Same rules as last time: COMPLEX+LAPLACE=CALCULUS.

In the following puzzle, letters represent digits. The same letter represent the same digit, but different letters must be different digit. All of them are from 0 to 9. Find each of the numbers corresponding to the letters. STEVE+JOBS=APPLES

1 point to @cellomaster8 from question 1! Q2 Is it possible to fit all 5 quadraminoes without overlap in a 4x5 rectangle? Explain.

first puzzle: llcaucsu

137 is the approximate denominator of the fine structure constant denoted by alpha, whose quantity is derived from several other fundamental constants of nature. The fine structure constant governs the strength of the em force, which in turn, controls how elementary particles interact with photons of light. As @LLLhk has told, 137 was the most common number for a single increase for coronavirus case rises in Chinese provinces. Let us take a toast to club members of China, who overcame the virus and are now able to enjoy life freely as though time had shifted a year back.