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 re: First question only by Ady TZIDON)

Ady, I don't see anything in the puzzle to exclude the answer I gave.

If Mathman wants to add conditions, though, I'll have a further think about it.

However, given that 'Normals tell the truth and lie completely at random' as opposed to 'Normals answer 'yes' or 'no' completely at random', it seems that only one question may be needed:

'Let 'status A' stand for the status (knight or liar) in which you will answer the following question:  If I were to ask you (in Status A) 'Is L the road to Normalville', would you (also in Status A) reply  'Yes''?

It seems that this would force normal to act throughout as either a knight or a liar, in which case see my comments on Thoughts on the second question for the solution. The added words would be of no effect if A was a knight or a liar.

 

Edited on October 8, 2012, 1:51 am

Posted by broll on 2012-10-08 01:33:12