# Math

There’s a short warm-up puzzle followed by the main puzzle. Thanks to Greg in Hungary (warm-up) and Jorn in Holland for suggesting these problems! *In my …

Featuring Professor Noga Alon. More links & stuff in full description below ↓↓↓ Extra footage: https://youtu.be/E-8YvnaumKU Recorded with Noga Alon at …

People are sharing a video about a US teacher who could not solve a problem from China’s university entrance exam, known as the gaokao. It’s a fairly …

I had many requests to solve problems like this. Watch the video to learn the trick! Sources …

People often email me that my videos helped them get a tech or finance job, which is really awesome, and I want to do more to help! So in this video I’m sharing …

Neil Sloane on the Van Eck Sequence… Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full …

This problem stumped me! But it has a pretty nice solution. Thanks to all patrons! Special thanks this month to Kyle, Michael Anvari, Richard Ohnemus, Shrihari …

Edmund Harriss introduces a very cool tiling and talks about Tribonacci Numbers. More links & stuff in full description below ↓↓↓ Numberphile Podcast: …

This test question in England confused many 11 year old students, and even some teachers. Some of you may see the answer right away, but please be nice: it’s …

This equation is not true with decimal numbers. But what if we use other number bases? This viral math meme turns into a nice little puzzle, which, as they say, …

Ben Sparks discusses the math behind a curious problem…. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) …

I’ve posted about this type of problem before. But now I present a simple formula to solve for all values of r. Thanks to Tony Hasler for figuring out this method!

Congratulations to Daniel Mai for winning the 2019 Raytheon MATHCOUNTS National Competition! Here’s the question that sealed his victory. Source …

8th grade students in Turkey have to solve problems like this one. I admit I got the wrong answer! Can you figure it out? Thanks to Ata from Turkey who …

Neil Sloane discusses peaceable queens and chess. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More …

Many students in the UK had difficulty with a similar problem on the GCSE exam. What’s the rectangle’s area, given the three circles are identical with radius r?

The 2017 GCSE exam featured a problem like this that confused many students. Learn how to solve it using Al-Kashi’s Theorem. Sources Emailed to me by Tom, …

Dr James Grime discusses the mathematics of extinction. More links & stuff in full description below ↓↓↓ Extras from this interview: …

Dr James Grime discusses ancestry and why we ALL have royal blood. See also our new video on family extinction at: https://youtu.be/z34XhE5oRwo More links …

Many students were confused about how to solve a tricky probability problem like this on the GCSE exam. Let’s go over how to solve it! Source …

There doesn’t seem to be enough information to solve this, but the answer works out magically. Thanks to all patrons! Special thanks this month to: Richard …

Can you imagine a late night talk show featuring mathematical puzzles? Well back in 1982 the great Johnny Carson interviewed the great Raymond Smullyan, …

A gigantic pie is shared with 100 guests, and each guest gets an increasing percentage of the remaining pie. Who gets the largest piece? Sources …

The legendary Elwyn Berlekamp died on April 9, 2019. In a final filming session with Numberphile, the games expert taught us how to play Amazons. More links …

Solve this equation. Then turn it upside down and solve it again. What a wonderful curiosity! The Talwalkar square (multiply by lines group theory) …

This is harder than it looks! Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Playlist to watch all videos on …

Featuring Ben Sparks discussing the Mandelbrot Set (and Julia Sets). More links & stuff in full description below ↓↓↓ More videos with Ben: …

There is now a mathematical theorem named after Sheldon. Sources Siouxland News article …

T-shirt and poster details below. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full …

Around the world, 17-18 year old students struggled to solve this kind of question. Can you figure it out? My video on the AM-GM inequality …

Can you see the pattern? Apparently geniuses can figure out the answer right away. Source …

Matt Parker has a new favourite number – again! More links & stuff in full description below ↓↓↓ Some notes from Matt on how far he has investigated: …

This one stumped me! This problem is part of the AIME, a qualifying test for the US Mathematical Olympiad team. The talented students who take the AIME only …

Fields Medallist Charlie Fefferman talks about some classic infinite series. More links & stuff in full description below ↓↓↓ Charles Fefferman at Princeton: …

It’s not so simple to solve for this simple answer. Thanks to all patrons! Special thanks this month to: Richard Ohnemus, Michael Anvari, Shrihari Puranik, Kyle.

This is a tricky SAT/GRE type problem that most people miss. Can you figure it out? Desmos animation https://www.desmos.com/calculator/kiswg6p0q7 Sources …

This is a fun basketball problem with an unexpected result! Sources http://www.math.utah.edu/~palais/mst/frequency.pdf …

Matt Parker discusses multiplicative persistence. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) Extra footage: …

Good luck with your picks! References https://www.ncaa.com/news/basketball-men/2019-02-13/absurd-odds-perfect-ncaa-tournament-bracket-put-perspective …

Just a short problem for the upcoming Pi Day! Can you figure it out? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Playlist …

42 is the only remaining (eligible) number below 100 which has not been represented as the sum of three cubes… 33 was cracked by Andrew Booker from the …

This is a fun little problem, can you solve it? The problem is from Manan Shah’s website Math Misery? which has many fun problems. Check his website out: …

The internet is loving this math trick which makes many calculations much easier! Sources/references …

How many points do you need to win and avoid relegation from the English Premier League? See Brady’s Blog for more info: …

The psychologist Max Wertheimer was friends with Albert Einstein. In 1934, he wrote a letter to Einstein that contained a simple brain teaser. Can you figure it out …