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Four people (Posted on 2011-11-28) Difficulty: 2 of 5
You meet four people. Their names are Gladys, Kate, Tom, and Tim. Each one is either a knight or a liar. They say the following statements.

Gladys:Kate and Tom are both liars.
Kate:Tim is a knight.
Tom:Gladys is a knight and Tim is a liar.

What are Gladys, Kate, Tom, and Tim?

See The Solution Submitted by Math Man    
Rating: 4.0000 (1 votes)

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Solution Explanation for Puzzle Answer Comment 3 of 3 |
(In reply to Puzzle Answer by K Sengupta)

Assume that Gladys is a knight. Then Kate's false statement  implies that Tim is a liar. Thus, Tom's statement is true in both the parts, so that he must be a knight. This contradicts Gladys' statement  that Tom is a liar. Therefore, it follows that Galdys is a liar so that, precisely one of Kate and Tom is a liar and the other is a knight. .......(i)

Also, Galdys is a liar. So at least one part of Tom's statement is false. Therefore, Tom is also a liar. 
Then, from (i), it immediately  follows that Kate is a knight, and her true statement implies that Tim is also a knight.
Summarizing,  we have:
Gladys -> Liar
Kate -> Knight
Tom -> Liar
Tim -> Knight

  Posted by K Sengupta on 2022-03-06 01:38:54
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