Three people stand in a line facing forward: Person 3 sees Persons 2 and 1; Person 2 sees Person 1; Person 1 sees no one. They are shown 3 red hats and 2 blue hats. Everyone is fitted with a hat. Person 3 says, 'I do not know my hat color.' Hearing this, Person 2 says, 'I do not know my hat color either.' What color hat is Person 1 wearing?
Red
If Persons 1 and 2 both wore blue hats, Person 3 would immediately know their own hat was red (since only 2 blue hats exist). Since Person 3 doesn't know, Persons 1 and 2 cannot both wear blue. Person 2 realizes this. If Person 1 were wearing a blue hat, Person 2 would deduce that Person 2 must be wearing red. But Person 2 also doesn't know! Thus, Person 1 cannot be wearing blue, meaning Person 1 must be wearing a red hat.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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