Problem 18: The Last Rolo

Image

My friend and I are sharing a pack of Rolos. When we reach the last one – which both of us want – we decide to flip a coin to see who gets it.

Annoyingly, we only have one coin which we know to be biased: the probability p of getting ‘heads’ satisfies:

  • p > 0
  • p ≠ 0.5
  • p < 1

Can we still use this coin to fairly decide who gets the last Rolo?