Three boxes are painted Red, Green, and Blue. Inside one box is a gold coin; the other two are empty. The Red box says: 'The coin is not in the Green box.' The Green box says: 'The coin is in this box.' The Blue box says: 'The coin is not in this box.' If exactly one statement is true, which box contains the gold coin?
The Blue box.
If the coin were in the Red box, both Red and Blue statements would be true. If in the Green box, both Green and Blue statements would be true. If in the Blue box, Red's statement is true ('not in Green'), Green's is false, and Blue's is false ('not in Blue' is false). This leaves exactly one true statement.
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: Easy. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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