Question

You are visiting a strange country in which there are just two kinds of people - truthtellers and liars. Truthtellers always tell the truth, and liars always lie. You hail the first two people you meet and say, "Are you truthtellers or liars?" The first person mumbles something you can't hear. The second says, "He says he's a truthteller. He is a truthteller and so am I." Can you trust the directions that these two may give you?

Answer 1

Answer:

No

Explanation:

Both people whom I meet are confusing lots: the first one who mumbles something that I don't hear, which means I cannot determine whether he is a truth-teller or a liar; The second one is a clear liar since he supports a fellow he knows alone, not I, and because he, like me, cannot hear what he says he is a party to the lie. The first guy does not speak clearly means he hides something deliberately and in strange country such ambiguous person cannot be trusted. The second one hastens to explain what the first says. How can the first one be sure of what the second one says if he doesn't listen to him? If both are friends or know each other, there is no reason why the first one mumbles if he is a truth-teller. If both are unknown to each other, the support for the second person by the first one is a gross lie. In such scenario, I cannot trust both of them.

Answer 2

Answer: Yes, you can trust them.

Explanation: Visualize the problem. The first one who mumbled something (person a) and the second one who you hear (person b).

Now let’s assume that Person A said ‘I am a truth teller.’ If he had said that and lied than Person B, who if he is also lying, would’ve said ‘he says he is a liar. He is a truth teller and so am i’ Because he always lies about everything.

Therefore, they are both truth tellers.