The Pirates Problem
By kamg on Feb 24, 2005
Inspired by Dave Brillhart's puzzle blog section, I've decided to create one of my own where I can post some of my favorite puzzles. Here my favorite: 5 pirates have a treasure of 100 gold pieces to split up after a long and profitable trip. The pirates are ranked by seniority and it is always the most senior pirate who decides how to divide up the booty amongst himself and any remaining pirates. However, the pirates are democratic: if the most senior pirate does not get at least 50% of the vote (including himself), then he is killed and the process repeats itself with the nextmost senior pirate proposing the breakup. The pirates are all completely rational and know that their compatriots are also completely rational. All of the pirates use the following priorities the drive their voting: 1. They don't want to get killed 2. They want to get the most money possible 3. They want to kill other pirates. How does the most senior pirate divide up the treasure such that he keeps as much as he possibly can for himself?