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