FILE No.194Unsolved
Among five people, A, B, C, D, and E, there is one phantom thief, X. Each of the five made two statements. In this puzzle, "P is lying" means "P is not completely truthful": at least one of P's two statements is false. The five testified as follows.
The phantom thief X is false in both statements. Besides X, there are people with exactly one false statement (at least one such person). Everyone else is true in both.
What can be said for certain about the phantom thief X?
If you get stuck, open the hints one at a time, in order.
What do the statements look like for a person who is "true in both"?
Assume who X is, and check the state of the others.
If a contradiction appears, discard the assumption.
What can be said for certain about the phantom thief X?
Choose the answer closest to the truth.
X is C or D
The answer is "X is C or D."
"Lying" here means a person who is not true in both statements (a person with only one true statement, or X, whose both are false). Checking exhaustively, only two cases hold: X is "D" or X is "C." No other assignment holds.
If A, B, or E is assumed to be the phantom thief X, the testimonies contradict each other.
Because the five testimonies are intertwined in a complicated way.
The cases on this site are fictional puzzles created for entertainment. Any resemblance to real people, organizations or events is coincidental.
© Unsolved Files
