Matt_Parker_2 | My response to being reverse-Dereked @mattparker2 | Uploaded 2 years ago | Updated 1 hour ago
The Riddle That Seems Impossible Even If You Know The Answer - Veritasium
youtube.com/watch?v=iSNsgj1OCLA

The unbelievable solution to the 100 prisoner puzzle - Stand-up Maths
youtube.com/watch?v=a1DUUnhk3uE

FACE REVEAL - The 1M Subs Q&A - Steve Mould
youtube.com/watch?v=GLADzZJqEyI

Main channel over here: youtube.com/standupmaths

And here is that paper: doi.org/10.1007/BF02986999
Legit free copy: cl.cam.ac.uk/~gw104/Locker_Puzzle.pdf