you are faced with two doors, one of which leads to heaven, the other to hell, and there are two guardians gaurding the doors, one on each side, and both look identical. The one guarding the door to hell will always lie, the other will always tell the truth and you are alowed one question to one guard. What would you ask them? remember, one question to only one guard!
The answer is that you would ask either guard " which door leads to hell?" because the one that lies will point at the opposite door meanwhile the one that tells the truth will point at the opposite door also, because it is the truth. so you would just go to the door they point at.