Three chests—Gold, Silver, and Bronze—stand in a row. One contains a brass key, one contains an iron key, and one is empty. The chest with the iron key always tells the truth, while the chest with the brass key and the empty chest always lie. The chests say: Gold: 'I do not contain the brass key.' Silver: 'The Gold chest contains the iron key.' Bronze: 'The Silver chest is empty.' Which chest contains which key?
The Gold chest contains the brass key, the Silver chest is empty, and the Bronze chest contains the iron key.
If Gold had the iron key, Gold would tell the truth, but Silver's statement ('Gold contains the iron key') would also be true, creating two truth-tellers. If Silver had the iron key, Silver's statement would be false, contradicting that the iron chest tells the truth. Thus, Bronze must contain the iron key and tell the truth ('Silver is empty'). Silver is empty and lies ('Gold contains iron' is false). Gold contains the brass key and lies ('I do not contain the brass key' is false).
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: Hard. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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