Sunday, 6 October 2013

Jack Higgins in 'Zulu'..

Thought exercise: 
(ht to Raymond Smullyan, a dude of the highest order)

I am an alien freshly arrived on Earth (the Planet of Knights, Knaves and Normals), with helpful inclinations and superior capabilities.

(For those of you who haven't read Smullyan, Knights always tell the truth, Knaves always lie, Normals can do either.)

I meet three people. I know that one is a Knight, one a Knave, and one a Normal, but not which is which. The first says: "We are screwing up the Planet, help us fix it." The second says "Don't listen to him, he's a Knave." I have one question to ask to determine who I should believe. What do I ask and to which one?

I really, really hope some people pick up on this one... :)