Ok here is now a classical logical problem. You may know it before. But if you don't know this story before and you find the right answer then you are a real genius.
Read it carefully !
Problem:
A boy wants to go to Village A. In his search, he found 2 ways without indication. But he know one of the 2 ways leads to Village A, and the other leads to Village B, but he don't know exactly which way leads to which Village. The he met tow guys, and he knew that one guy is a liar and the other is honest, but also he didn't know who is the honest one of the tow guys. What he did is that : He chose by chance one of them and asked him a question Q, and then he followed the way indicated by this guy, which is the right way.
So what was the question Q he asked ?