Lie Detector

Class: A teacher.

Lie Detector

Few days back CDS invented the first lie detector in the world. But they wanted to test it before launching the product in public. So, Arsh, Saad and Fawad are called upon to test a lie detector.

Arsh says: -I think I can solve twenty questions in an hour-. BUZZZZZZ, goes the lie detector. -Ok-, he says, -10 questions-. And the machine is silent.

Saad says: -I think I can solve 15 questions-. BUZZZZZZ, goes the lie detector. -Allright, 5 questions-. And the machine's silent.

Fawad says: -I think...-, BUZZZZZZ goes the machine.