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The same three chaps are being tested by a wise man.

"I have three white caps and two black caps", he says, "You will close your eyes. I will put a hat onto each of your heads, and hide the others. You will not be able to see your own hat. You have to deduce what colour hat you are wearing."

So he does, and the chaps open their eyes, and there is a pause, and then one of the chaps says...

Solutions saying "they all must have white caps or it wouldn't be fair" are no good.

Imagine you are the person who wins, person 1. He looks and sees two caps. he imagines he has a black cap. He puts himself in the position of the next chap. If he saw two black caps he would have immediately said "I have a white cap", but he doesn't. Person 2 doesn't know. Person 3 has a white cap and person 2 doesn't know, and person 3 doesn't know, so neither sees a black cap and person 1 must have a white cap!

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