Prisoner and Hats puzzle (variation)

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SUMMARY

The Prisoner and Hats puzzle variation involves ten prisoners, each wearing a hat that is either red or white, with a total of three white hats and seven red hats. The prisoners can only see the hats of those in front of them and must deduce the color of their own hat based on the statements made by others. After several prisoners declare their uncertainty, Prisoner #1 confidently states he knows the color of his hat. This conclusion is reached because the lack of information from the previous prisoners indicates that they see a configuration that allows Prisoner #1 to deduce his hat must be white.

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Here is a brain teaser I came across recently.

Ten prisoners are arranged single file in a line. They are sorted so that the shortest prisoner (prisoner #1) is in the front, and the tallest prisoner (prisoner #10) is in the back. The are all looking forward (in the direction of #1). They all close their eyes. Another man (not in line) has ten hats, three white and seven red. This man gives each prisoner a hat. The prisoners then put on their hats. The prisoners then open their eyes. They can only see the hat colors of the prisoners in front of them (i.e. Prisoner #6 can see the hats and colors of 1-5, but not 6-10). They cannot see the color of their own hat. The prisoners are aware that there are three white hats and seven red.

Prisoner #5 says: "I don't know the color of my hat."
Prisoner #4 says: "I don't know the color of my hat."
Prisoner #3 says: "I don't know the color of my hat."
Prisoner #2 says nothing.
Prisoner #1 says: "I know what color hat I have."

What color hat did Prisoner #1 have and how did he figure it out?
 
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The #1´s hat is:
Red

Logic:
#5 didn´t see 3 white hats. #4 didn´t see 2 white hats. #3 didn´t see 1 white hat. #2 should know that there was no white hats with #2 and #1.
 
Red
Logic: #5 didn't see 3 white hats, meaning he saw one of these combinations: RRRR,RRRW,RRWR,RRWW,RWRR, RWRW,RWWR, WRRR, WRRW, WRWR,WWRR.

Of these 11 possibilities, 3 have no pair that #4 would see. In other words, #4 didn't see RWW, RWRW, WWR.

Which means #3 knows the possibilities are: RRRR, WRRR, RRRW, WRRW, RRWR, WRWR, RWRR, or WWRR. Only two of those possibilities have #1 wearing a white hat and both of those possibilities have #3 wearing a red hat. If #3 didn't know his color, then #1 had to be wearing a red hat. Not only is #1 wearing a red hat, but #2 is wearing a red hat, as well.
 

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