My friend told me this complex story. Everyone in it is either a knight, knave, or liar (more than one person can have the same status). Knights always tell truths, liars always lie, and knaves always alternate every statement.

Everyone knew the status of everyone else except for my friend (he knew nothing at first). If anyone lied about what someone said, they didn’t lie about who, when, or whether they said it; they only lied about what the person said. The story goes as follows.

Aaron and Bill were talking to me.
Aaron told me what he was.
At this point, I could tell what Aaron was.
Bill told me one thing that he wasn’t.
Aaron told me that Cassie was a knight.
I then could figure out what Cassie was.
Bill told me that Cassie was a knave.
I thought about this for a minute.
I soon found that the previous thing Bill said allowed me to know for sure what the last of the three people were.

What type is everyone? The puzzle is solvable.

(In reply to re(5): Pointing out...Tristan?!? by Brian Wainscott)

"If anyone lied about what someone said, they didn’t lie about who, when, or whether they said it; they only lied about what the person said."

Let me reword it to make it more clear. If anyone lied about what someone said, they didn't lie about who, when or whether they said it (and didn't ommit it completely either). The lie only means that the person did not say what was claimed or anything that is essentially the same.

For example, if a liar said, "Cassie said she was a knight," than Cassie really could have said, "I like socks," or, "I am a knave," but not, "I am neither a knave nor a liar."

Posted by Tristan on 2004-02-04 18:37:31