This is a cool riddle of logic that I heard recently. It is supposed to be drawn out so I'll try to describe it as best as I can. Four prisoners of war are sentenced to death by firing squad. They line them up from north to south, all of them facing north (so that they are in line facing the person in front of them, Directions are unimportant North South etc..) Each of them is wearing a hat, they are told that there are two black hats and two white hats. If ONE of them can say for sure what color hat they are wearing, they are all set free. The person in front, who cannot see the hat colors of any of his comrades, is wearing a white hat. The man behind him is wearing a black hat, and the man behind him is wearing a white hat. The last man is behind a wall wearing a black hat so he cannot see the hat colors of the men in front of him. All of them are aware of their physical positions; for example, the man in the front knows that there are two men behind him, and another behind a wall etc... The only thing they don't know is their own hat color and the hat colors of those behind them. It looks like this: Black | White Black White They can only see the hat colors of the people in --> direction from them, with the exception of the last man behind the wall. They have exactly ten minutes before they are executed. Which one of them would be able to know their hat color and why?