A Problem with Infinite Hotel Keys - Numberphile

Tom Crawford poses a problem and finds an answer -- Learn more and apply to Jane Street’s WiSE program in New York, London or Hong Kong: https://jane-st.co/wise-numberphile (channel sponsor) -- More links & stuff in full description below ↓↓↓ Extra footage from this video - we take it further - https://youtu.be/txoJDJxhv4E Infinity on Numberphile - https://www.youtube.com/playlist?list=PLt5AfwLFPxWKORZ3UeTKlJiJa-89BBz3t 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 Tom Crawford teaches at both the University of Oxford and the University of Cambridge. At Oxford he is the Public Engagement Lead at the Department for Continuing Education, and a fellow at St Edmund Hall. At Cambridge he is a Fellow at Robinson College. Tom's own YouTube channel (Tom Rocks Maths): https://www.youtube.com/channel/UCRfo-DAifrP3lzcxUHtGm_A Patreon: http://www.patreon.com/numberphile Numberphile is supported by Jane Street. Learn more about them (and exciting career opportunities) at: https://bit.ly/numberphile-janestreet We are also grateful for support from Ben Delo. NUMBERPHILE Website: http://www.numberphile.com/ Video by Brady Haran and Pete McPartlan Numberphile T-Shirts and Merch: https://teespring.com/stores/numberphile Brady's videos subreddit: http://www.reddit.com/r/BradyHaran/ Brady's latest videos across all channels: http://www.bradyharanblog.com/ Sign up for (occasional) emails: http://eepurl.com/YdjL9