Puzzle #1 Solution:
Person "C" is the one who called out.
Since D has not called out, that means the two colours in front of D must be different. As a result, C's hat must be different to B's, so he knows it's black.
Since D has not called out, that means the two colours in front of D must be different. As a result, C's hat must be different to B's, so he knows it's black.
Four men are sentenced to be punished. However, their kind leader offers them a way out - if they are clever enough:
In order to escape punishment, one of them must call out and correctly identify the colour of their hat within ten minutes.
After 1 minute, one of them calls out. Which one, and why is he so confident about the colour of his hat?
- He arranges for them to be buried up to their necks in the sand in the desert (as shown in the diagram) in a straight line, with three on one side of a brick wall, and one on the other, each wearing either a black or white hat.
- The wall cannot be seen through (i.e. A and B can only see their own sides of the wall).
- They cannot turn their heads to see the people behind them.
- The men are blindfolded when they are buried, and know that there are two white hats and two black hats, but they do not know who is wearing which colour.
- C can see B, and D can see C and D.
- No communication is permitted between them.
In order to escape punishment, one of them must call out and correctly identify the colour of their hat within ten minutes.
After 1 minute, one of them calls out. Which one, and why is he so confident about the colour of his hat?