The following two facts are known about Adam, Bert, and Carl:

1) Of Adam, Bert, and Carl, there is one knight, one knave, and one liar.
2) Adam said once, "Bert said that Carl isn't a knight."

Can you ask one yes/no question to one person and figure out who is who? If not, how many questions must you ask?

(In reply to (-) * (+) = - by turki)

truki wrote: "could anyone define (KNAVE)!! i don't know exactly what does it mean. is he the person who sometimes lies and somtimes tells the truth? that' it?"

A Knave, as I understand it, is a person who alternates truths and lies, unless the puzzle explicitly states otherwise, as Tristan did in the puzzle "I'm a knight ! Really !", where he wrote: "When I visited the Knights and Liars Archipelago, one island I visited was called Liontruth. The tourism had a great influence on the island, so much that the knaves on the island spoke differently from most knaves. They didn't have to follow an alternating pattern, but could tell truths (like knights always do) and lie (like liars always do) in whatever pattern they wanted." 

In this puzzle a Knave would have to alternate.

 

 

Edited on February 27, 2005, 9:11 am

Posted by Penny on 2005-02-27 09:05:19