I am just beginning to learn propositional logic, and my text book had this question:
Each inhabitant of a remote village always tells the truth or always lies. A villager will give only a “Yes” or a “No” response to a question a tourist asks. Suppose you are a tourist visiting this area and come to a fork in the road. One branch leads to the ruins you want to visit; the other branch leads deep into the jungle. A villager is standing at the fork in the road. What one question can you ask the villager to determine which branch to take?
I understand the textbook answer; which is:
“If I were to ask you whether the right branch leads to the ruins, would you answer yes?”
But my question is if this answer is equally valid:
"Do either of these roads from this fork in the road lead to the ruins?"
Now the reasoning I have is that we know that one of the roads in the fork leads to the ruins. The villager, if he is a liar, will say no. (lie). If he is honest, he will say yes.
Is this sound?