Knights and Knaves

Some puzzles from the book "What is the name of this book" by Raymond D Smullyan

There is a wonderful book by Raymond D. Smullyan that everyone who likes puzzles should read.

Its name is: What Is the Name of This Book?: The Riddle of Dracula and Other Logical Puzzles.

Here are some puzzles from this book. All the puzzles below are about the “Island of Knights and Knaves.” Knights always tell the truth and Knaves always lie.

Puzzle 1: A stranger from out of town meets three inhabitants A, B, C standing in a garden. He asks A: “Are you a Knight or a Knave?” A mumbles something the stranger could not hear so he asks B: “What did he say?” B said: “He said he was a Knave.” C said: “Don’t believe B, he is lying !” What are B and C (Knights or Knaves)?

Puzzle 2: Now the stranger meets two people A and B

A says: “At least one of us is a Knave.” What are A and B?

Solutions are here

And here is one more that I will leave you to solve on your own:

Puzzle 3: The stranger from out of town meets three other inhabitants A, B, C. He asks A: “How many Knight are among you?” A mumbles something the stranger could not hear so he asks B: “What did he say?” B said: “He said there is one Knight among us.” C said: “Don’t believe B, he is lying !” What are B and C (Knights or Knaves)?