[Mathematical logic (other).]

On an island, there live two tribes - natives and aliens. It is known that natives always tell the truth, and aliens always lie. A traveler hired a local islander as a guide. On the way, they met a man. The traveler asked the guide to find out which tribe this man belonged to. The guide returned and reported that the man claimed to be a native. Was the guide a native or an alien?
Think about what the person who was met answered the guide.

## Solution

The second native, whoever he may be, would answer affirmatively to the question: "Are you a native?" Therefore, the guide did not deceive the traveler, which means the guide is also a native.

## Answer

The guide is a native.