Oxford’s sum of sines interview question

Solve this to get into Oxford! 2021 Oxford MAT Questions https://www.maths.ox.ac.uk/system/files/attachments/test21.pdf 2021 Oxford MAT Solutions https://www.maths.ox.ac.uk/system/files/attachments/websolutions21.pdf Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive a commission for sales. (As an […]

What is a Number? – Numberphile

Featuring Asaf Karagila. More links & stuff in full description below ↓↓↓ Asaf is a UKRI Future Leaders Fellow. Asaf’s blog – http://karagila.org Asaf’s Twitter – https://twitter.com/AsafKaragila Numberphile podcast featuring Asaf – https://youtu.be/b6GLCTh5ARI All the Numbers with Matt Parker – https://youtu.be/5TkIe60y2GI Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also […]

Trick to convert kilograms and pounds. #Shorts

Not everyone knows this simple method to convert kg and lbs quickly in your head! #Shorts Reference https://en.wikipedia.org/wiki/Kilogram#cite_note-1 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you purchase through these links, I may be compensated for purchases made on […]

Solve for the radius of the three cornered circles

Thanks to Umesh for the suggestion! If the large circle has a radius equal to 1, what is the radius of each small circle? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I […]

Stones on an Infinite Chessboard – Numberphile

Another curious puzzle and number sequence from Neil Sloane. More of our videos with Neil: http://bit.ly/Sloane_Numberphile More links & stuff in full description below ↓↓↓ Neil Sloane is founder of the On-Line Encyclopedia of Integer Sequences: https://oeis.org More of our videos with Neil Sloane: http://bit.ly/Sloane_Numberphile Pebbling a chessboard with Zvezda Stankova: https://youtu.be/lFQGSGsXbXE Patreon: http://www.patreon.com/numberphile Numberphile […]

How to remember pi #Shorts

Sir James Hopwood Jeans developed this simple way to remember pi nearly one hundred years ago. #shorts References http://content.time.com/time/subscriber/article/0,33009,789058-4,00.html https://en.wikipedia.org/wiki/Piphilology Other sentences to remember pi https://www.tiktok.com/@pinkpencilmath/video/7006829332748373250 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links […]

Incredible logic puzzle for 11 year olds!

I bet this one will give many adults a good challenge too. Thanks to Pett for the suggestion! Special thanks this month to: Kyle, Mike Robertson, Michael Anvari, Daniel Lewis, Robert Zarnke. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Singapore International Math Olympiad Challenge (SIMOC) 2015 – Primary 5 Paper, problem 24. Sample Papers Subscribe: […]

So that’s why it’s called pizza…

The secret to pizza’s name origin is mathematics, or so the legend goes… #Shorts Images https://commons.wikimedia.org/wiki/File:Pizza_Tikka.JPG#filelinks https://commons.wikimedia.org/wiki/File:Volume_of_a_pizza.svg Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive a commission for sales. (As […]

Conic Loaf of Bread – Numberphile

Featuring Cliff Stoll – http://bit.ly/Cliff_Videos More links & stuff in full description below ↓↓↓ Cliff’s website: https://www.kleinbottle.com Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, a Simons Foundation initiative dedicated to engaging everyone with the process of science. https://www.simonsfoundation.org/outreach/science-sandbox/ And support from The Akamai Foundation […]

Can You Solve This Number Pattern?

Versions of this puzzle have gone viral on the internet. The puzzle stumps adults but is surprisingly easy for many children. Can you figure it out? Thanks to Thomas from Vietnam for suggesting a version of this puzzle! SIMOC 2015, Primary 3 contest, problem 18. Sample Papers Problems https://drive.google.com/file/d/0B0-8qjwNLbpgblFnZVZGZjNXX2M/view?resourcekey=0-vF8vaNzyrTYuMoRPUEsZIg Answer key https://drive.google.com/file/d/0B0-8qjwNLbpgVWhheW9za29ERk0/view?resourcekey=0-i4EZCxROBmtAS1kdXd-row Data scientist approach […]

Bertrand’s Paradox (with 3blue1brown) – Numberphile

Featuring Grant Sanderson, creator of 3blue1brown. Extra footage from this interview: https://youtu.be/pJyKM-7IgAU 3blue1brown video on the shadow a cube: https://youtu.be/ltLUadnCyi0 More links & stuff in full description below ↓↓↓ 3blue1brown: https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw Grant on The Numberphile Podcast: https://youtu.be/A0RH93XvSyU Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, […]

How mathematicians wish Merry Christmas

This equation has a secret meaning. #shorts Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive a commission for sales. (As an Amazon Associate I earn from qualifying purchases.) This has […]

The Largest Small Hexagon – Numberphile

Featuring Dr James Grime. More links below. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full description below ↓↓↓ Ron Graham’s paper: http://www.math.ucsd.edu/~fan/ron/papers/75_02_hexagon.pdf James Grime: https://www.singingbanana.com His YouTube channel: https://www.youtube.com/user/singingbanana More James on Numberphile: http://bit.ly/grimevideos Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We […]

The Most Wanted Prime Number – Numberphile

Featuring Neil Sloane. Visit https://gift.climeworks.com/numberphile to give the gift of CO₂ removal. Use code NUMBERPHILE10 for 10% off your purchase in December (sponsor) More links & stuff in full description below ↓↓↓ Neil Sloane is the founder of The OEIS: https://oeis.org More videos with Neil: http://bit.ly/Sloane_Numberphile Prime Playlist: https://bit.ly/PrimePlaylist Note the 17350-digit prime we feature […]

A tricky fraction question from India!

Thanks to Tanmay for the suggestion! And do check out Tanmay’s channel Mr. Whiteboard for mathematics videos in Hindi: https://www.youtube.com/channel/UCNBjkDt8Xxn9I4Nb_Cn6ZoA Thanks to Tony H. and Nestor for pointing out mistakes in an earlier version of this video! This question is adapted from BYJU’S National Aptitude Test (BNAT). 0:00 Problem 0:51 Hint 3:19 Solution References Doubtnut […]

Omicron (the symbol) in Mathematics – Numberphile

Professor Tony Padilla discusses the Greek letter Omicron. More links & stuff in full description below ↓↓↓ More Numberphile with Tony: http://bit.ly/Padilla_Numberphile More Numberphile on Covid: https://bit.ly/339Wuxf Don Knuth on Numberphile: https://youtu.be/mPn2AdMH7UQ and https://youtu.be/v678Em6qyzk Objectivity video about The Almagest: https://youtu.be/QW29uaD78OU Tony Padilla is based at the University of Nottingham: https://www.nottingham.ac.uk/physics/people/antonio.padilla Pre-order Tony’s upcoming book on […]

Challenging problem given to 12 year olds – square in a quadrant

Thanks to John H. for the suggestion! A square is inscribed in a quarter circle with two of its vertices on the arc. If the radius equals 1, what is the area of the square? Special thanks this month to: Robert Zarnke, Kyle, Mike Robertson, Michael Anvari, Daniel Lewis. Thanks to all supporters on Patreon! […]

Hitomezashi Stitch Patterns – Numberphile

Ayliean MacDonald discusses Hitomezashi Stitch Patterns. More links & stuff in full description below ↓↓↓ More about Ayliean MacDonald: https://linktr.ee/Ayliean Previous video with Ayliean (Tower of Hanoi set to music): https://youtu.be/PGuRmqpr6Oo Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, a Simons Foundation initiative dedicated to […]

Tricky test question – maximum probability of a red ball

Thanks to Amish for the suggestion! This is a tricky one from India’s challenging JEE Mains test. Can you figure it out? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive […]

Witness Numbers (and the truthful 1,662,803) – Numberphile

Featuring Matt Parker – more Parker links below. Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full description below ↓↓↓ MATT PARKER STUFF Stand-Ups Maths on YouTube: https://www.youtube.com/user/standupmaths Matt’s website: https://standupmaths.com Matt’s Books (Amazon): https://amzn.to/3absFfV Matt’s playlist on Numberphile: http://bit.ly/Matt_Videos Parker Square Merch: https://numberphile.creator-spring.com/listing/the-parker-square Numberphile is supported […]

How to make railway timetables (with graphs) – Numberphile

Featuring Hannah Fry discusses Train Graphs. More links & stuff in full description below ↓↓↓ Hannah’s website, including links to her many and varied projects… and latest books: https://hannahfry.co.uk Her latest book (with Adam Rutherford) is the Complete Guide to Absolutely Everything (Abridged): https://amzn.to/30Mr6UE Hannah on Numberphile: http://bit.ly/hannah_vids Hannah on the Numberphile podcast: https://youtu.be/KKCjQWmUwv8 Numberphile […]

Infinitely Many Touching Circles – Numberphile

Featuring Matt Henderson. Check out https://www.kiwico.com/Numberphile and get 50% off your first month of any subscription. (sponsor) More links & stuff in full description below ↓↓↓ Matt Henderson: https://twitter.com/matthen2 More videos with Matt Henderson: https://bit.ly/MattHendersonPlaylist Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, a Simons […]

What is the rule? Challenging question for 8 year old students

A challenging problem was posted to Reddit HomeworkHelp and it was said to be given to gifted 8 year old students. Can you figure it out? Reddit HomeworkHelp [3rd Grade Math] Need help with question 1. I seriously can’t figure it out. from HomeworkHelp Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of […]

A Video about the Number 10 – Numberphile

Featuring the friendless number 10 for our 10-year anniversary… James Grime is back where it all began. More links & stuff in full description below ↓↓↓ James is at The City Ground – see the original 11.11.11 video at: More James Grime on Numberphile: http://bit.ly/grimevideos James Grime’s website (with links to his various activities): https://www.singingbanana.com […]

A nice chord problem from Bangladesh!

This problem is adapted from the 2021 Bangladesh Mathematical Olympiad (BDMO). I thank Mumtahina for the suggestion! Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive a commission for sales. (As […]

Can you solve this tricky sum from Indonesia?

This one stumped me at first. Can you figure it out? Thanks to Gusti for the suggestion! Special thanks this month to: Daniel Lewis, Robert Zarnke, Fiona Harper, Kyle. Mike Robertson, Michael Anvari. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Reference https://brainly.co.id/tugas/2903461 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). […]

The Doomsday Algorithm – Numberphile

Featuring James Grime. Check out https://www.kiwico.com/Numberphile and get 50% off your first month of any subscription. (sponsor) More links & stuff in full description below ↓↓↓ More James Grime videos: http://bit.ly/grimevideos James Grime: https://www.singingbanana.com John Conway: http://bit.ly/ConwayNumberphile Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, […]

Key to the Tower of Hanoi – Numberphile

Featuring Ayliean MacDonald… Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full description below ↓↓↓ Extra footage from the making of this video: https://youtu.be/KTq0KLx6cQg More about Ayliean MacDonald: https://linktr.ee/Ayliean Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, […]

The Time Albert Einstein Went Viral For Helping A 14 Year Old Student With Homework

Imagine being stuck on a math problem and then having Albert Einstein help you out. For one lucky student in 1952 this actually happened! 0:01 Problem 2:28 Hint 3:00 Solution Physics Today. “Albert Einstein and the high school geometry problem” David Topper, Dwight E. Vincent, 19 Dec 2017, 1945-0699 https://physicstoday.scitation.org/do/10.1063/PT.6.4.20171219a/full/ Public domain image of Albert […]

Adults Stumped By Test Question For 13 Year Olds

This is a tricky question from Singapore’s PSLE. I don’t think I would have solved it easily in a timed exam. So let’s work it out carefully in our own time. Thanks to Jul, Abdul, and Junwen for the suggestion! References https://mothership.sg/2021/10/psle-coin-question/ https://cnalifestyle.channelnewsasia.com/living/psle-math-problem-got-everyone-calculating-and-asking-282256 Other problems from Singapore Area of a claw Overlapping circles in a […]

Music on a Clear Möbius Strip – Numberphile

The mathematical genius of JS Bach – featuring Marcus Du Sautoy. More links & stuff in full description below ↓↓↓ See books by Marcus, including his latest “Thinking Better: The Art of the Shortcut” — https://amzn.to/3j5FygD Marcus’ website with latest info: https://www.simonyi.ox.ac.uk Marcus on Twitter: https://twitter.com/MarcusduSautoy Other Marcus videos on Numberphile: https://bit.ly/Marcus_Numberphile Marcus on the […]

Trapped Water and Tiny Holes – Numberphile

Tom Crawford shows why water doesn’t fall through a sieve with small enough holes. More links & stuff in full description below ↓↓↓ Tom Crawford’s website, with links to his work and other outreach: https://tomrocksmaths.com More Tom videos on Numberphile: http://bit.ly/Crawford_Videos Tom on the Numberphile Podcast: https://youtu.be/_HwKGncsGo0 Numberphile is supported by the Mathematical Sciences Research […]

What is the area shaded in green?

Thanks to Jumar for the suggestion! Can you solve this interesting geometry problem? 0:00 Problem 1:10 Similar triangles 2:29 Solution Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! If you buy from the links below I may receive a commission […]

Finite Fields & Return of The Parker Square – Numberphile

Matt Parker introducing Finite Fields and re-visits the infamous Parker Square… Extra footage & become a millionaire by winning The Parker Prize: https://youtu.be/hn8SwBhhDvU More links & stuff in full description below ↓↓↓ The Original Parker Square video: https://youtu.be/aOT_bG-vWyg The paper featured in this video: https://arxiv.org/abs/1908.03236 MATT PARKER STUFF Stand-Ups Maths on YouTube: https://www.youtube.com/user/standupmaths Matt’s website: […]

A nice sum from France solved in 3 ways!

This problem is adapted from a national math competition exam in France. Special thanks this month to: Michael Anvari, Robert Zarnke, Fiona Harper, Kyle, Jamal Jackson. Mike Robertson. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Sorry for the repost! In my original video (https://youtu.be/_2GPAzpSyDQ) I had a calculation mistake around 7:10 in method 3. I […]

A nice Olympiad qualifying question from the Philippines

If a semicircle and its flipped copy are placed side by side, how much distance do they span from end to end? This is a neat problem adapted from a Mathematical Olympiad Qualifying Test in the Philippines. Can you figure it out? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). […]

Stacked Dice Trick – Numberphile

A third dice trick with Ben Sparks – see the trilogy of tricks at: https://bit.ly/Dice_Trilogy More links & stuff in full description below ↓↓↓ Ben Sparks: https://www.bensparks.co.uk And his YouTube: https://www.youtube.com/c/SparksMaths More Ben Sparks on Numberphile: http://bit.ly/Sparks_Playlist Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are also supported by Science Sandbox, […]

Can you solve this tricky Oxford logic puzzle?

This problem is adapted from an Oxford University admissions question. They say if you can solve this in your head, you are a genius 😉 Alex Bellos’s column on The Guardian https://www.theguardian.com/science/2021/jul/12/did-you-solve-it-oxford-university-admissions-questions Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address at end of many videos). I may not reply but I do consider all ideas! […]

The Strange Orbit of Earth’s Second Moon (plus The Planets) – Numberphile

Featuring Matt Henderson… Check out Brilliant (get 20% off their premium service): https://brilliant.org/numberphile (sponsor) More links & stuff in full description below ↓↓↓ More videos with Matt: https://bit.ly/MattHendersonPlaylist Follow his work on Twitter at: https://twitter.com/matthen2 Previous video with Matt (Chaotic Balls): https://youtu.be/6z4qRhpBIyA Numberphile is supported by the Mathematical Sciences Research Institute (MSRI): http://bit.ly/MSRINumberphile We are […]