This might have the answer but the video I watched doesn’t seem to confirm this. What do you think?
by Matthew Cobb
Many people around the world will be eating more chocolate than usual over the next few days. This popped up in my Twitter feed, from magician @RichardWiseman, re-tweeted by mathematician and science-writer @SLSingh:
[Yes, I know it’s a very old puzzle]
JAC: The solution is here.