Randall Munroe of XKCD talks about a great puzzle at the end of this 10 min video: https://www.ted.com/talks/randall_munroe_comics_that_ask_what_if https://www

Randall Munroe of XKCD talks about a great puzzle at the end of this 10 min video: https://www.ted.com/talks/randall_munroe_comics_that_ask_what_if https://www.ted.com/talks/randall_munroe_comics_that_ask_wha...