# Yes/No logic puzzle

1. Nov 26, 2016

### Mr Davis 97

1. The problem statement, all variables and given/known data
An explorer is captured by a group of cannibals. There are two types of cannibals--those who always tell the truth and those who always lie. The cannibals will barbecue the explore unless he can determine whether a particular cannibal always lies or always tells the truth. He is allowed to ask the cannibal exactly one question. Find a question that the explorer can use to determine whether the cannibal always lies or always tells the truth.

2. Relevant equations

3. The attempt at a solution
I am not sure where to start. Is there a systematic way to formulate the appropriate question with propositional logic and truth tables, or must one just have divine inspiration?

2. Nov 26, 2016

### PeroK

You could always ask the cannibal whether he is a dolphin. If he says he is a dolphin then he's a liar.

But, I guess that's not the sort of question you are expected to find?

3. Nov 26, 2016

### Math_QED

I actually laughed on that one, but it's a correct answer.