PUZZLE : try to solve it or accept ur defeat ;)

ali.infoseek · 10-12-2008, 05:32 PM

There is a prisoner who is about to be executed. The king decides to give him one last chance to live.

There are 2 doors, the life door and the death door. There is one guard standing by each door. Those two guards know which door is the life door and which is the death door. However, one of them always tells the truth and the other always tells a lie. There is no way you can identify which door is the life door or the death door. There is no way you can distinguish who is the one telling the truth.

The prisoner can only ask one guard one question. Then he needs to choose a door to walk in. If he walks in the death door, then he will be executed. If he walks in the life door, he can have a new life.

He did choose the life door and lived. What was the question he asked? How did he choose the door after he got the answer from one of the guards?

vijaysomarajz · 10-12-2008, 05:43 PM

To Guard A: What will be Guard B's answer if I ask "If Door A is the way to Life Door?"
Then take the other door.

Am I correct...

hima1 · 10-12-2008, 06:06 PM

Hi Abbas,

Here's the explanation.........

Let's the Two doors be x and y........
X is Life door and Y is Death door.............

Case 1) Guard A is the one who tells Truth :-

In this case the Prisoner asks "Which Door wud the other Guard ask me to take to save my Life?". Since the man tells the truth, he would know that Guard B would misguide the traveller by lying......
he would answer by saying that "He would ask you to take path Y"........
so if the Prisoner assumes that the Guard A says the truth, he would know that the other Guard would lie so he is left wid only path X"

Case 2) The Guard A is the one who lies :-

If the same ques i.e. "Which path wud the other Guard ask me to take to get to the city?"
is asked to the liar he would reply " Guard B wud ask u to take path Y".
now this is a lie...

So if the Prisoner assumes that the Guard A is a liar, he wud know that he wud give a false statement about the other Guard.....so the correct path is path X

Based on both assumptions, irrespective of the Guard telling a truth or a lie.......the answer remains the same......!!!!

Phew... Is that right Abbas??

aravarasan9 · 11-12-2008, 05:43 AM

Ask anyone of the guards:"Which door the other guard will show if i ask him for a life door?".
Follow the door different from that of the answer.That is the life door

ali.infoseek · 11-12-2008, 10:34 AM

Hello friends,

3 Replies and 80 viws !!!

77 accepted their defeat