I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle(UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.
Three men decide to have a shooting contest to the death. Each man has one gun, and each gun contains just one bullet. They draw straws to determine the order in which they will shoot. The rules are simple:
If the first man to fire shoots the second man, then the third man has to shoot the first man. If the first man to fire shoots the third man, then second man has to shoot the first man. Oh, and the first person has to shoot.
What should first man do to ensure that he survives the contest?