Brain Teasers
Tribal Truth
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?
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?
Hint
Try using the "Trial and Error" Method.Answer
LOGIC:Suppose there are any 2 tribal people of the same tribe standing adjacent to each other.
Then, if one of them is asked about the tribe of the other, he'll say "TRIBE X".
If both are in tribe X, then he'll tell the truth, that is "TRIBE X".
X X - TRIBE X
If both are in tribe Y, then he'll lie, that is "TRIBE X".
Y Y - TRIBE X
Similarly, if their tribes are different, then the answer will always be "TRIBE Y".
X Y - TRIBE Y
Y X - TRIBE Y
So from the question, A and B are in different tribes, so are B and C and so are C and D.
Since there are two types of tribes only, A and C are in the same tribe while B and D are in the same tribe.
Now, since according to D, A will call C a liar (TRIBE Y), in spite of both of them being in the same tribe, D is lying.
Hence B and D are liars (TRIBE Y), while A and C are honest (TRIBE X).
A - TRIBE X
B - TRIBE Y
C - TRIBE X
D - TRIBE Y
Hide Hint Show Hint Hide Answer Show Answer
What Next?
View a Similar Brain Teaser...
If you become a registered user you can vote on this brain teaser, keep track of which ones you have seen, and even make your own.
Solve a Puzzle
Comments hidden to avoid spoilers.
Follow Braingle!