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
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Comments
Congrats on your first teaser!
Yes! I totally got that teaser. great job that was really fun. it is really similar to the "Isle of Begile" from Mindtrap. Is that where you got the idea?
Totally loved this! Had a lot of fun solving it. Thanks for a great tease!
This made my brain hurt, mabey I should wait till I'm more awake to try these kinds of teasers.
Great teaser. Your explanation in the answer is correct but there's a much quicker and easier way - just assume A is in say X and go thruogh the logic. If it works, you were right. If not - swap them!
Great teaser. Your explanation in the answer is correct but there's a much quicker and easier way - just assume A is in say X and go through the logic. If it works, you were right. If not - swap them!
Great teaser. Your explanation in the answer is correct but there's a much quicker and easier way - just assume A is in say X and go through the logic. If it works, you were right. If not - swap them!
Great teaser. Your explanation in the answer is correct but there's a much quicker and easier way - just assume A is in say X and go through the logic. If it works, you were right. If not - swap them!
Sorry - no idea why my comment came up 4 times! Could someone please remove the extras??
hey peanut, i agree with u, i think u didnt see the hint i have given...
Your explanation is nice, but not necessarily needed. It can be solved based purely on the assumptions (2 of each tribe) and the responses given. Given the responses, D is lying so he is in tribe Y. C says "D is in Y", so C is in X. B says "C is in Y," which is a lie so B is in Y. So finally, based on A's statement "B is in Y" and the assumptions, we know that A in X.
Conversely, if you leave all the statements the same but change D's statement to say: "A will say the B is in tribe Y", then D would be in X, C would be in Y, B would be in X and A would be in Y.
Conversely, if you leave all the statements the same but change D's statement to say: "A will say the B is in tribe Y", then D would be in X, C would be in Y, B would be in X and A would be in Y.
im afraid i didnt understand this.
It's really not very hard ;)
It's like that one where you have a liar and someone who speaks truth and ask either one if the other would say that the one you are speaking to is the liar. Say yes, they tell the truth, say no - they lie. Or you could ask them if they are a girl, and work it out from sheer obviousness
But either way, it wasn't half bad
It's like that one where you have a liar and someone who speaks truth and ask either one if the other would say that the one you are speaking to is the liar. Say yes, they tell the truth, say no - they lie. Or you could ask them if they are a girl, and work it out from sheer obviousness
But either way, it wasn't half bad
that was really fun i didnt think i'd get it but i actually did=D
The easy way is to see that D lied in the first place (A didn't say what he claimed... and saying something is an absolute truth). So you know D is from Tribe Y. Then C told the truth. Then B lied. There you go
hey i got this teaser...until i read the answer!i still got it right though
Nice teaser, very clever made me think some....
-Coltonr1-
-Coltonr1-
one of the rare good teasers out here...atleast made me think out of my head...
cleverly made, keep it up!
and this makes me wait for more of your teasers...
cleverly made, keep it up!
and this makes me wait for more of your teasers...
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