Knights and Knaves question

Question

Assume A, B and C are either knights or knaves.  A says: “B is a knight, if and only if C is a knight.” B says “C
is a knave or A is a knave.” What are A,B and C? (Knights always tell the truth and knaves always lie.)

 

How can I do this problem with truth tables?

 

Answer 1

You've got two statements that must be true:

 

1.  A↔(B↔C)

 

2.  B↔(¬C∨¬A)

 

Set up a truth table for [ A ↔ (B↔C) ] ∧ [ B↔ (¬C∨¬A) ]. Whenever this statement is true that is a solution.