After person dies he is about to enter Hell but then God is always kind and so gave him an option to choose his own destiny of Hell or Heaven.
There are 2 doors one leads to Hell and the other as expected to heaven.
Both the doors are guarded by 1 guard each and one of them always tells a lie and the other always tells the truth.
The option man has is to ask only one
question and decide which is the Heavens door and if he can get into heaven, he will remain in heaven forever.
So now the question is comes as to what did the person ask to the guards ?
The answer can be found on MBA Forum
If you can search well. Dont try to copy the text and Google it as its well mingled ( according to me )