| Topic Name: |
Brainteaser |
| Message Name: |
By Deduction- |
| Date Posted: |
01/29/2002 |
| In Reply To: |
Perhaps someone can help solve this question.
3 prisoners and a jailer. A bag with 3 black and 2 red hats. The prisoners are blind folded and each selects a hat and puts it on his head. The jailer will let them go if anyone of them can identify the color of the hat on his head and explain why he knew the color. In other words they just can't guess. They can see each others hats but not their own. The jailer asks the first prisoner if he knows and he says no. Then
he asks the second prisoner and he says no. The third prisoner is blind but when he is asked he correctly identifies the color and explains how he knew it. |
| Message: |
Our hero must have a red hat! There are only 3 cases where he might have a black hat -
1 2 3
(A) R R B
(B) R B B
(C) B R B
When #1 passed, case B was eliminated (#1 would see both black hats and know he had red).
Next, if #2 saw a black hat on our hero, he would know that either case A or C was true, and thus know he himself had a red hat.
Finally, since gallant #3 knew that neither A nor B nor C was true, all the remaining cases had him with a RED HAT.
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