Problem Eight: Tribal Truth
Oct 22nd, 2006 by Allen
There are two tribes, X and Y, in a jungle such that people belonging to tribe X always speak the truth while those in tribe Y always lie.
Suppose you come across 4 such people A, B, C, D:
A B C D
A says: “B is in tribe Y.”
B says: “C is in tribe Y.”
C says: “D is in tribe Y.”
D says: “A will say that C is in tribe Y.”
If there are two people from each tribe, can you deduce who is from which tribe?
Update: Solutions are posted!