Since Mr Lau Chia Ming wants it so much.. =X
Answer to the 3rd August post:
To solve this question, you have to calculate it in the other way. The 3 customers gave $9 each to the manager, in total gave $27 to the manager. They kept their $3 to themselves ( The manager gave them back) , keeping $1 each. Out of $27 that manager received, he got cheated by the waiter $2. After that waiter cheng ren cuo wu, and gave the manager back $2, $27 is in the manager's pocket while $3 is fen kai-ed and is in three customers' pockets. Haha..
Q2. John was walking a path in the forrest. While walking, he came into a folkroad. He was certain that one of that road was the safe way to the town, but another one was the road to the hideout of the thieves. Then, there was an old man in the middle of the folkroad. This old man was either a truth-teller, who always tells the truth, or a lier, who always lie. If this old man is a truth-teller, he never lies. If he is a lier, he never tell the truth. If you were John, what one question would you ask to find the safe way to the town? You are only allowed to ask one single question.
Hint : - 1 X - 1 = + 1