Top Puzzle 2: The Island of Truth and Lies | Puzzles for Interview - Interview Preparation PDF Download

Introduction

This is a puzzle that involves two tribes: the "Lie Tribe" and the "Truth Tribe". The "Lie Tribe" always lies, while the "Truth Tribe" always speaks the truth. In this puzzle, you meet three people from these tribes and ask them a question.

Question

You ask the first person, "Which tribe do you belong to?" However, the person responds in their own language, which you don't understand. The second person translates the answer for you and tells you that the first person belongs to the "Lie Tribe". The third person then tells you that the second person is lying.

Solution

To solve this puzzle, we need to determine which tribe the third person belongs to. Here's how:

Assumption 1: First Person is from "Truth Tribe"
If we assume that the first person is from the "Truth Tribe", then he would tell the truth and claim that he belongs to the "Truth Tribe". This would mean that the second person is lying because he translated the answer as "Lie Tribe". Therefore, the third person would be telling the truth, and he belongs to the "Truth Tribe".
Assumption 2: First Person is from "Lie Tribe"
Now, let's assume that the first person is from the "Lie Tribe". In this case, he would lie and claim that he belongs to the "Truth Tribe". The second person would then translate the lie as "Lie Tribe". Once again, the third person would be telling the truth, and he belongs to the "Truth Tribe".

Conclusion

In both assumptions, the third person is telling the truth, which means he belongs to the "Truth Tribe".