Math

Can you solve this challenging Valentine’s Day problem? Thanks to Stéphane from Belgium 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 an
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Can you solve this “coffin” problem? Thanks to Rahul for the suggestion! Special thanks this month to: Kyle, Mike Robertson, Michael Anvari. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Adapted from problem 4 of Jewish Problems by Tanya Khovanova, Alexey Radul https://arxiv.org/abs/1110.1556v2 Coffin Problem ft. blackpenredpen: Cube and Cube Root (Mu Prime Math) Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1
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This was asked to students in Indonesia. Can you figure it out? Special thanks this month to: Michael Anvari, Kyle, Mike Robertson. Thanks to all supporters on Patreon! Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I cannot reply to everyone but I consider all ideas! Like many YouTubers I use popular software
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The Dynamical Uniform Boundedness Conjecture with Dr Holly Krieger. Extra from this interview: https://youtu.be/v4LWFzTyhpU Dr Krieger on the Numberphile Podcast: https://youtu.be/QmfQQzjpdpM More links & stuff in full description below ↓↓↓ More videos with Holly: http://bit.ly/HollyKrieger Holly’s website: https://www.dpmms.cam.ac.uk/~hk439/ She is the Corfield Lecturer at the University of Cambridge as well as a Fellow at Murray
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Happy Pi Day! At 3/14/15 at 9:26 the time will be accurate to pi for 7 decimal places. What’s your favorite fact about pi? Links to proofs and more below in the description. 1. The definition 00:10 Related: the area of circle intuitive explanation 2. Pi is irrational 00:47 Proof (video) Proof (blog post) http://mindyourdecisions.com/blog/2013/11/08/proving-pi-is-irrational-a-step-by-step-guide-to-a-simple-proof/
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A little extra trick based on some of the Mobius cutting videos we recently published. Featuring Tadashi Tokieda. More links & stuff in full description below ↓↓↓ MORE: http://bit.ly/tadashi_vids Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported by the Mathematical Sciences Research Institute
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What fraction of the entire circle is shaded? Special thanks this month to: Michael Anvari, Kyle, Mike Robertson. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Jobbings, A. (2011). The Mathematical Gazette https://www.cambridge.org/core/journals/mathematical-gazette/article/9564-two-semicircles-fill-half-a-circle/6365F0D492DF2E682E71A891C782CAF6 The chalice problem Azimuth Project (John Carlos Baez) Geometry Puzzles Folding proof by Greg Egan http://math.ucr.edu/home/baez/mathematical/semicircle_puzzle_egan.gif Cut The Knot https://www.cut-the-knot.org/proofs/Semicircles.shtml Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send
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Tadashi Tokieda cuts various combinations of loops and Mobius loops – with surprising results. More links & stuff in full description below ↓↓↓ Part 2: https://youtu.be/mh3eMt09EAs And more: http://bit.ly/tadashi_vids Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported by the Mathematical Sciences Research Institute
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Catch a more in-depth interview with Ben Sparks on our Numberphile Podcast: https://youtu.be/-tGni9ObJWk Check out Brilliant (and get 20% off) by clicking https://brilliant.org/numberphile More links & stuff in full description below ↓↓↓ Golden seeds limited edition T-Shirt: https://teespring.com/NP-Seeds More Golden Ratio stuff: http://bit.ly/Golden_Ratio More Ben Sparks Numberphile videos: http://bit.ly/Sparks_Playlist Ben’s Twitter: https://twitter.com/SparksMaths Ben’s website: www.bensparks.co.uk
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Thanks to Himanshu from India for sending me this problem! It was part of a math competition where you had about 1 minute to solve each problem (I admit I took much longer). Can you figure out the area of the folded rectangle? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Playlist to watch all videos on MindYourDecisions: https://www.youtube.com/playlist?list=UUHnj59g7jezwTy5GeL8EA_g Thanks to
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Cliff Stoll is passionate about Klein Bottles. More links & stuff in full description below ↓↓↓ Don’t miss the video about how he uses a robot to store 1,000 bottles UNDER his house… https://youtu.be/-k3mVnRlQLU More videos on Klein Bottles: http://bit.ly/KleinBottles ACME Klein Bottles: http://bit.ly/ACME_Klein Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook:
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Patreon: http://www.patreon.com/numberphile More links & stuff in full description below ↓↓↓ Tony Padilla is an associate professor of physics at the University of Nottingham. Here he discusses the zeta function and Apéry’s Constant. More Tony videos: http://bit.ly/Padilla_Numberphile Tony’s Tweet: https://twitter.com/DrTonyPadilla/status/828527018081918976 Roger Apéry pics courtesy of François Apéry Numberphile is supported by the Mathematical Sciences Research
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Photomath can’t solve this, and neither can Mathway, Symbolab, or Desmos. Can you? I explain how you can. A similar problem was given to high school students in Massachusetts, and you really have to know what you’re doing to figure it out. Thanks to all patrons! Special thanks this month to: Shrihari Puranik Richard Ohnemus
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This problem went viral after it appeared on a Math Olympiad test for talented students in Singapore. It’s not a trick question! Here’s the problem, which I have very slightly re-worded for clarity. Blog post (detailed text explanation): http://mindyourdecisions.com/blog/2015/04/14/when-is-cheryls-birthday-answer-to-viral-math-puzzle/ Source: https://www.facebook.com/kennethjianwenz/photos/a.173663129479243.1073741827.167504136761809/385751114937109/?type=1&theater Official Solution: http://mothership.sg/2015/04/p5-logic-question-is-actually-a-math-olympiad-question-for-sec-3-and-4-students/ Albert and Bernard have just become friends with Cheryl, and they
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French numbers can pose problems for non-native speaker – especially when you move beyond 70. Also discussing problems with phone numbers and commas! More links & stuff in full description below ↓↓↓ Featuring Dr Paul Smith from the University of Nottingham. The French and marks out of 20: http://www.youtube.com/watch?v=QzrRkhU248A A little extra unlisted bit from
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Can you solve for the shaded area? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can’t always reply! Like many YouTubers I use popular software to prepare my videos. You can search for animation software tutorials on YouTube to learn how to make videos. Be prepared–animation is time
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Runners X, Y, Z compete in a 1000 m race. If X gives Y a 50 m start, they finish together; if X gives Z a 69 m start they finish together. What start does Y have to give Z so they finish together? Source This is adapted from India’s Civil Services Exam. Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1
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First in a series of videos about knots. Here we have Carlo H. Séquin from UC Berkeley. More links & stuff in full description below ↓↓↓ More videos to come at: http://bit.ly/Knot-a-Phile Edit and animation by Pete McPartlan. Film and interview by Brady Haran With thanks to Rob Scharein for the use of his software
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This challenging geometry problem appeared on one of the hardest math competitions (the Putnam exam), and there is a neat way to solve it! The Putnam Exam has legendary difficulty: the average (median) score is usually 1 out of a possible 120 points. No calculators allowed though, and you have to prove everything very carefully.
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More links & stuff in full description below ↓↓↓ Brady’s Movember Page: http://bit.ly/BradyMo See full description for list of Connect 4 links. John Tromp’s page: http://bit.ly/TrompNumberphile James Allen’s Connect Four book: http://bit.ly/AllenBook James Allen: http://james.fabpedigree.com/ OEIS: https://oeis.org/A212693 Victor Allis paper: http://bit.ly/AllisPaper NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by
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Thanks to Surjadi from Indonesia for the suggestion! Twitter Cshearer41 A square is split into five rectangles with equal areas. What’s the area of the square? pic.twitter.com/wtuEjxMASI — Catriona Agg (@Cshearer41) July 11, 2020 solution by @birkhofyan pic.twitter.com/3EIij7DjaU — Birkan Yıldız (@birkhofyan) July 11, 2020 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video).
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Thanks to Matej for suggesting this problem! This is from a math competition for 14 year olds in Croatia. While the problem is challenging, “you should be able to solve it” using elementary geometry and algebra. Can you figure it out? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Playlist to watch all videos on MindYourDecisions: https://www.youtube.com/playlist?list=UUHnj59g7jezwTy5GeL8EA_g This is the only
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Thanks to Robin for the suggestion! Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can’t always reply! Like many YouTubers I use popular software to prepare my videos. You can search for animation software tutorials on YouTube to learn how to make videos. Be prepared–animation is time consuming
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Our Pi Playlist (more videos): http://bit.ly/PiPlaylist Pi is famously calculated to trillions of digits – but Dr James Grime says 39 is probably enough. More links & stuff in full description below ↓↓↓ An extra note from Dr Grime: “Since pi39 ends in 0, you may think we could use pi38 instead – which has
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The harmonic series and the elusive Euler–Mascheroni constant. More links & stuff in full description below ↓↓↓ Featuring Dr Tony Padilla. Audible: http://www.audible.com/numberphile Extra footage: https://youtu.be/eRGN8ThZfhU Videos about -1/12: http://bit.ly/minus_twelfth Tony at the LHC: https://youtu.be/sVYUqMRolaA (via Sixty Symbols, our physics channel) Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets:
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Another pass at the Monty Hall Problem – see the last video and a new “express explanation” at: http://bit.ly/MontyHallProb More links & stuff in full description below ↓↓↓ Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Numberphile is supported by the Mathematical Sciences Research Institute (MSRI):
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Why do cicadas emerge every 17 years – featuring Steve Mould. Steve is on Twitter at https://twitter.com/MouldS More links & stuff in full description below ↓↓↓ See Steve talkabout Benford’s Law at: http://youtu.be/XXjlR2OK1kM And discuss Pi at: http://youtu.be/ZPv1UV0rD8U The golden ratio video will be coming soon. Keep an eye on Numberphile. NUMBERPHILE Website: http://www.numberphile.com/ Numberphile
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The 1947 Stanford Competitive Examination included a version of this problem. Reference https://www.cut-the-knot.org/Outline/Arithmetic/DivisionBy72.shtml Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can’t always reply! Like many YouTubers I use popular software to prepare my videos. You can search for animation software tutorials on YouTube to learn how to
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Who can solve this one? Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can’t always reply! Like many YouTubers I use popular software to prepare my videos. You can search for animation software tutorials on YouTube to learn how to make videos. Be prepared–animation is time consuming and
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Can you pass this logic test that stumps many people? References https://brilliant.org/problems/the-boxes/ http://www.dailymail.co.uk/femail/food/article-3905480/Are-smart-solve-beer-burger-brainteaser-Tricky-maths-puzzle-sweeping-web-harder-looks.html Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video). I consider all ideas though can’t always reply! Like many YouTubers I use popular software to prepare my videos. You can search for animation software tutorials on YouTube to learn how to
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Everyone’s details below in full description. Please leave a comment about YOUR favourite number!!! More links & stuff in full description below ↓↓↓ Thanks YouTube EDU people. This video featured in order: Brady Haran (who makes Numberphile): http://www.bradyharan.com/ Derek Muller chose i – http://www.youtube.com/1veritasium Hank Green chose 2 – http://www.youtube.com/scishow Steve Spangler chose 13 –
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Our Pi Playlist (more videos): http://bit.ly/PiPlaylist Steve Mould (tau) and Matt Parker (pi) go head-to-head. More links & stuff in full description below ↓↓↓ See our tau video: http://www.youtube.com/watch?v=83ofi_L6eAo And check our Pi videos: http://www.youtube.com/playlist?list=PL4870492ACBDC2E7C Matt Parker: http://www.standupmaths.com/ Steve Mould: http://www.stevemould.com/ NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by
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Beautiful Dragon Curves, Fractals and Jurassic Park. Featuring Rob Eastaway. More links & stuff in full description below ↓↓↓ Rob’s website: http://www.robeastaway.com/ Thanks to Matthew Ward and Faraz Barzideh who helped Brady out with some curves! The book Jurassic Park is by the late Michael Crichton. NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets:
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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 https://www.theguardian.com/science/2017/jun/19/did-you-solve-it-pythagorass-best-puzzles https://puzzling.stackexchange.com/questions/52787/who-get-the-biggest-piece Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Playlist to watch all videos on MindYourDecisions: https://www.youtube.com/playlist?list=UUHnj59g7jezwTy5GeL8EA_g This is the only channel to feature math topics suggested by people around the world. Support on Patreon
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Outtakes: https://youtu.be/Wrj1Kl6CHIQ Who’s Who in the video: https://www.numberphile.com/pi-million More links & stuff in full description below ↓↓↓ Patreon: http://www.patreon.com/numberphile Numberphile T-Shirts: https://teespring.com/stores/numberphile 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
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The ancient Babylonians used a number system with base 60 (sexagesimal). More links & stuff in full description below ↓↓↓ Tablet image courtesy of Bill Casselman and Yale Babylonian Collection – more at http://www.math.ubc.ca/~cass/Euclid/ybc/ybc.html This video features Thomas Woolley – he tweets at https://twitter.com/#!/thomasewoolley NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe:
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Thanks to http://www.audible.com/numberphile More links & stuff in full description below ↓↓↓ Here’s the paper Dr Grime discusses: http://arxiv.org/pdf/1101.4470.pdf OEIS: http://oeis.org Dr Grime: http://singingbanana.com 1729: http://youtu.be/LzjaDKVC4iY NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by Brady Haran Patreon: http://www.patreon.com/numberphile Brady’s videos subreddit: http://www.reddit.com/r/BradyHaran/ Brady’s latest videos across all channels: http://www.bradyharanblog.com/
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Thanks to Taka for the suggestion! This is a fun and challenging geometry problem. Special thanks this month to: Michael Anvari, Kyle. Thanks to all supporters on Patreon! http://www.patreon.com/mindyourdecisions Source What's the width of the rectangle?#geometry #maths #puzzle pic.twitter.com/FPOod0dKrB — pangolin (@panbtc) February 25, 2020 Subscribe: https://www.youtube.com/user/MindYourDecisions?sub_confirmation=1 Send me suggestions by email (address in video).
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Brady’s view on people who write: “FIRST” – http://youtu.be/CmRh9tFYC68 More links & stuff in full description below ↓↓↓ Dr James Grime on the Pisano Period – a seemingly strange property of the Fibonacci Sequence. Available Brown papers: http://periodicvideos.blogspot.co.uk/2013/09/brown.html With thanks to http://www.youtube.com/AlanKey86 James Grime on Twitter: https://twitter.com/jamesgrime The Alan interview: http://www.youtube.com/watch?v=acTrvMlpuxA Lagrange Points: https://www.youtube.com/watch?v=mxpVbU5FH0s NUMBERPHILE
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The internet is loving this math trick which makes many calculations much easier! Sources/references Fascinating little life hack, for doing percentages: x% of y = y% of x So, for example, if you needed to work out 4% of 75 in your head, just flip it and and do 75% of 4, which is easier.
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George Dantzig, William Sidis, Srinivasa Ramanujan? Who was the real Good Will Hunting? More links & stuff in full description below ↓↓↓ Maths in Good Will Hunting: http://www.youtube.com/watch?v=iW_LkYiuTKE This video features Numberphile’s very own mathematics superstar – Dr James Grime. NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by Brady
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Check out How Not To Be Wrong by Jordan Ellenberg: http://bit.ly/HowNotToBeWrong More links & stuff in full description below ↓↓↓ And special Kindle offer: http://bit.ly/Wrong_Special This video features Dr James Grime – http://singingbanana.com Cheers to Thomas Oléron Evans for inspiring James: http://www.mathistopheles.co.uk/maths/covering-all-the-bases/ Support us on Patreon: http://www.patreon.com/numberphile NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile
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