6
$\begingroup$

Of three persons A, B and C, one always lies while the other two always speak the truth.

  • C asked A: "Do you always speak the truth, yes or no?"
  • A said something that C could not understand.
  • So C asked B: "What did A just say?"
  • B replied: "A said NO."

So, who is the liar?

$\endgroup$
9
$\begingroup$

The answer is:

B is the liar.

The reason:

If A is a truth-teller, he has correctly answered YES (I am a truth-teller).
If A is a liar, he also has answered YES (lying, as he is a liar).

So A must have said YES, and B must be lying when he claims that A said NO.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.