Four Men in Hats: Answer
Shown above are 4 men buried up to their necks in the ground. They can not move so can only look forward. Between A and B is a brick wall which can not be seen through. They know that between them are 4 hats, 2 are black and 2 are white, but they do not know which color they are wearing. In order to avoid being shot one of them must call out to the executioner the color of their hat. If they get it wrong, everyone will be shot. They are not allowed to talk to each other and have 10 minutes to fathom it out.
Qestion: Which one of them calls out ?
Answer: C calls out that he is wearing a black hat.
Qestion: Why is he 100% certain of the color of his hat ?
Answer: After a while, C comes to the realization that he must answer. This is because D can't answer, and neither can A or B. D can see C and B, but can't determine his own hat color. B can't see anyone and also can't determine his own hat color. A is in the same situation as B, where he can't see anyone and can't determine his own hat color. Since A, B, and D are silent, that leaves C. C knows he is wearing a black hat because if D saw that both B and C were weraing white hats, then he would have answered. But since D is silent, C knows that he must be wearing a black hat as B (who he can see) is wearing a white hat.
Source: Unknown
Back to CamWorld