University tests your math skills for Wi-Fi password

This is a math teacher's dream: an integral calculus problem that actually went viral! In 2018, news outlets reported that students at a university in China had to solve this math problem for the WiFi password in a dining hall. This is actually a pretty neat problem. Watch the video for its solution! Thanks to Elto for sending me a similar problem that was posted in a restaurant in Canada. 0:00 problem 1:22 solution 6:36 history Related video: story of 355 over 113 https://www.youtube.com/watch?v=JnRnvehbcQs Beijing News (Chinese) http://tech.ifeng.com/a/20180907/45156013_0.shtml Daily Mail http://www.dailymail.co.uk/news/article-6142997/Chinese-university-canteen-makes-students-answer-calculus-question-unlock-access-Wi-Fi.html CNET https://www.cnet.com/news/wi-fi-access-only-granted-to-students-in-china-after-they-solve-a-puzzle/ Chronology of computation of π https://en.wikipedia.org/wiki/Chronology_of_computation_of_%CF%80 https://en.wikipedia.org/wiki/Zu_Chongzhi https://commons.wikimedia.org/wiki/File:Liu_hui.jpg https://commons.wikimedia.org/wiki/File:%E7%A5%96%E5%86%B2%E4%B9%8B%E9%93%9C%E5%83%8F.jpg Pi wordplay https://mathworld.wolfram.com/PiWordplay.html Members get early access to videos YouTube members https://www.youtube.com/channel/UCHnj59g7jezwTy5GeL8EA_g/join Patreon members https://www.patreon.com/mindyourdecisions Support the channel with a one-time donation https://www.paypal.com/donate/?hosted_button_id=REZRY3QRQPYQA 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 Amazon. As an Amazon Associate I earn from qualifying purchases. This does not affect the price you pay. Book ratings are from January 2025. My Books (worldwide links) https://mindyourdecisions.com/blog/my-books/#worldwide My Books (US links) Mind Your Decisions: Five Book Compilation https://amzn.to/2pbJ4wR A collection of 5 books: "The Joy of Game Theory" rated 4.2/5 stars on 564 reviews http://amzn.to/1uQvA20 "The Irrationality Illusion: How To Make Smart Decisions And Overcome Bias" rated 4.2/5 stars on 55 reviews http://amzn.to/1o3FaAg "40 Paradoxes in Logic, Probability, and Game Theory" rated 4.2/5 stars on 81 reviews http://amzn.to/1LOCI4U "The Best Mental Math Tricks" rated 4.3/5 stars on 148 reviews http://amzn.to/18maAdo "Multiply Numbers By Drawing Lines" rated 4.5/5 stars on 57 reviews http://amzn.to/XRm7M4 Mind Your Puzzles: Collection Of Volumes 1 To 3 https://amzn.to/2mMdrJr A collection of 3 books: "Math Puzzles Volume 1" rated 4.4/5 stars on 138 reviews http://amzn.to/1GhUUSH "Math Puzzles Volume 2" rated 4.2/5 stars on 45 reviews http://amzn.to/1NKbyCs "Math Puzzles Volume 3" rated 4.3/5 stars on 38 reviews http://amzn.to/1NKbGlp 2017 Shorty Awards Nominee. Mind Your Decisions was nominated in the STEM category (Science, Technology, Engineering, and Math) along with eventual winner Bill Nye; finalists Adam Savage, Dr. Sandra Lee, Simone Giertz, Tim Peake, Unbox Therapy; and other nominees Elon Musk, Gizmoslip, Hope Jahren, Life Noggin, and Nerdwriter. My Blog https://mindyourdecisions.com/blog/ Twitter https://twitter.com/preshtalwalkar Instagram https://www.instagram.com/preshtalwalkar/ Merch https://teespring.com/stores/mind-your-decisions Patreon https://www.patreon.com/mindyourdecisions Press https://mindyourdecisions.com/blog/press