Q.

You are standing before two doors. One of the path leads to heaven and the other one leads to hell. There are two guardians at each door. One of them always tells the truth and the other always a lie.You can only ask  only one question to only one of them . Your aim is to find the door to heaven.

What question will you ask?

A.

Ask ‘ If I ask the other guard that which door leads to heaven, what door would the guard answer?’. The answer will always lead to hell – hence choose the other door.