[Peekay]

This is an easy one for Friday...(I searched for this one but couldn't find it in previous posts)

While on the land of Knights (people who always tell the truth) and Knaves (people who always lie), I came across two inhabitants resting under a tree. I asked one of them, "Is either of you a Knight?" From his answer I immediately knew what kind he was and also what the other guy was. Can you tell?

[Guest]

Knave while the other was a Knight. You know because he could not have been telling the truth when he answered "No."

[Peekay]

Knave while the other was a Knight. You know because he could not have been telling the truth when he answered "No."

Please note that I did not disclose what the answer was. BTW, these type of puzzles are sometimes called "meta-puzzles" since it seems like not enough information is given. But, in fact, they can be solved!

[Guest]

'neither of us is a knight'

[Guest]

"No" or "Neither of us" which means he is a Knave and the other is a Knight. This is the only option if the answer is negative.

Had he answered affirmatively there are 3 possibilities: Both are Knaves, or the person answering is a Knight and the other is either Knight or Knave. Since the question states that from the answer given you can determine the character of both persons, the answer must have been "no".

Please note that I did not disclose what the answer was. BTW, these type of puzzles are sometimes called "meta-puzzles" since it seems like not enough information is given. But, in fact, they can be solved!

Edited May 27, 2011 by Copernicus

[Peekay]

"No" or "Neither of us" which means he is a Knave and the other is a Knight. This is the only option if the answer is negative.

Had he answered affirmatively there are 3 possibilities: Both are Knaves, or the person answering is a Knight and the other is either Knight or Knave. Since the question states that from the answer given you can determine the character of both persons, the answer must have been "no".

Copernicus - You nailed it! Couldn't have explained it better.

"just_tonight" and "thirdtimescharm" were also correct in their answers but were only lacking in a thorough explanation.

Have a good weekend everyone!

[Guest]

Yes.

Though the answer to the question is 'Yes', it is not the answer given by the inhabitant asked. As a Knight would answer "Yes" regardless if his companion were a Knight or Knave, and a Knave would also answer "Yes" if the other resting inhabitant were a Knave, the answer received must have been "No", with the answerer being a Knave and his companion being a Knight. Nevertheless, the answer is 'Yes' because 'I can tell.'

[Peekay]

Yes.

Though the answer to the question is 'Yes', it is not the answer given by the inhabitant asked. As a Knight would answer "Yes" regardless if his companion were a Knight or Knave, and a Knave would also answer "Yes" if the other resting inhabitant were a Knave, the answer received must have been "No", with the answerer being a Knave and his companion being a Knight. Nevertheless, the answer is 'Yes' because 'I can tell.'

Good one - Dej Mar!

[Guest]

Good one - Dej Mar!

Yes, Peekay, I'm afraid I must relinquish your given "Nailed It" trophy over to Dej Mar who more carefully read the question than I. Oh semantics, how I love thee...

[Hidden G]

GOD i am so late ,i wish i was here earlier to answer this question(i was studuing for exams) cz my answer would be true as the both above

[Guest]

He must have answered "no" which can not be true since that would be a paradox, so it is a lie, he is a knave, and the other one is a knight.

He did not answer "yes" since there is no way to deduce if that is true or a lie.