In a secret society, every member is either a Truth-teller (who always tells the truth) or a Liar (who always lies). You meet two members, X and Y. X says, 'We are both Liars.' What are X and Y?
X is a Liar, Y is a Truth-teller
If X were a Truth-teller, his statement 'We are both Liars' would be true, which is a contradiction because a Truth-teller cannot be a Liar. Therefore, X must be a Liar. Since X is a Liar, his statement is false, meaning it is not true that they are both liars. Thus, Y must be a Truth-teller.
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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