Alrighty, here’s an interesting puzzle that I ran across at work the other day.

There are four men. There are four hats, two black and two white. Each man is wearing a hat. None of the men know the colour of the hat they are wearing. There is a wall separating one of the men (Man A) from the other three, so that he cannot see them. All of the men are facing towards the wall. The three men are standing in a row so that Man B can see only the wall, Man C can see Man B and Man D can see Man C and B.Hat Puzzle

The men are about to be shot, but are given a final option: if at least one man can say what colour hat he is wearing, all four men go free. If none of the men speak, or if one speaks, but is incorrect, all the men will be shot. After about 1 minute, one man speaks.

  1. Who speaks?
  2. How can he be 100% sure he is right?

Hint #1: The guy who speaks only takes a minute because he’s waiting to see if someone else speaks first.

Hint #2: The four men have been provided all of the information above.