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Guest Message by DevFuse
Simple but challenging logic puzzle
4 replies to this topic
Posted 11 June 2012 - 07:46 AM
While a red mark was placed on the forehead of each of three blindfolded men seated facing each other in a circle, they were told that the the mark might be either red or white. Upon removal of the blindfolds, each was to raise his hand if he saw at least one red mark, and then to take it down if he could logically deduce the color of his own mark. All three hands were quickly raised, but then one of them lowered his hand. How did he know?
Posted 13 June 2012 - 08:45 AM
Excellent... interpretation by both of you of the solution... the key to the solution was thinking from perspective of other persons also (why they are not raising hands)... Most people put themselves in the place of the first person, but to solve this one, you must then also put yourself in the place of a second man.
Posted 13 June 2012 - 03:54 PM
Half Fast Well, everyone raised their hand, so everyone sees at least one red dot. I'm guy A, the others are B and C. I think to myself, if I have a white dot, guy B would see a red dot (on C) and a white dot (on A, me), and since guy C raised his hand, B would know his dot is red because mine is white. Same with guy C looking at A (me) and B. If neither one can deduce this readily, I must have a red dot also.
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