In Normalville, every inhabitant is either a knight, a liar, or a normal. Knights always tell the truth. Liars always lie. Normals tell the truth and lie completely at random. You are going to Normalville when you see a fork in the road. There are two ways to go. One of them leads to Normalville. You see three inhabitants by the fork, A, B, and C. You know that only one of them is a normal, but you are not sure who it is. In two "yes" or "no" questions, how do you find the way to Normalville? (Each question can only be addressed to one person, but it can be a different person for each question.)
(In reply to no cigar
by Ady TZIDON)
There is a solution. The trick is that your first question should identify one of them that is definitely not a normal. Then, you can ask your second question to this person.
Posted by Math Man
on 2012-10-06 09:15:20