An Englishman, an American and Ah Beng were called upon to test a lie detector.
The Englishman says, "I think I can empty 20 bottles of beer." BUZZZZZZZ, goes the lie detector. "Okay, I was lying, I can only empty 10 bottles."And the machine is silent.
The American says: "I think I can eat 15 hamburgers" BUZZZZZZ, goes the lie detector. "Okay, I was lying. I can only eat 8 hamburgers."And the machine is silent.
Then Ah Beng says, "I think …………" BUZZZZZZ, goes the machine.

(If you did not catch this one, the machine buzzed because Ah Beng cannot think )