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.

The only admission to immediately identify an individual is by A saying "I am a liar". By this statement we know he is a knave.

Aaron's first statement was a lie so his next would have to be the truth. C is a knight.

All 3 types could say that "I am not a liar" or "I am not a knave" so it would be impossible to tell unless another comment was made. If Bill had said I am not a knight he would have to be a knave because neither a knight or liar would say that because it would have been truth or lie respectively. Bill's first comment did not give him away so he did not say he wasn't a knight. Bill's second comment tells us that he is a liar because of 2 lies in a row. Bill would have to have said "I am not a liar".

Aaron= Knave
Bill= Liar
Cassie= Knight

PS: Is the "friend" a person in the story. Liar, Knave, or knight???

Posted by Jesse on 2004-02-02 19:37:45