Three friends, Alan, Bob and Cecil, sit down at a park bench. Each of them is a Knight or Liar and each knows what the other two are.
Forgetful Bob, well known for his flamboyant hats that are either red, white or blue, asks Alan: "What colour hat am I wearing today?"
Alan replies: "There is a chance Cecil would tell you it's blue. If you saw it, there is a chance you would say it is white."
Bob sighs, "I should have asked Cecil - he always tells me the truth..."
What colour hat is Bob wearing?
Obviously it's red. Bob has very wisely asked the knight which color it is, and he has let us know that "there is a chance" that the other two may say either of the lies available to them ( although there is also a chance they would use the other), so of course the hat is red.
oops...I just realized this is an old problem and others have already answered...oh well, it was still fun.
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Posted by Goldwing
on 2005-10-18 15:45:34 |