Knights always tell the truth,liars always lie,and knaves alternate between truths and lies.

Suppose you ask a native,"Are you a knight,a liar,or a knave?" The native answers,and you are able to figure out what he is.

What is the native?

If they say that they are a knight, then they could be anything.

If they say that they are a knave, then they are either a liar or a knave.

If they say that they are a liar, then they must be a knave.

Therefore, the native is a knave.

 

Posted by Math Man on 2011-06-17 22:53:42