Wednesday, May 2, 2007

Right way to heaven

After a person's death , he is heading towards heaven. On his way he finds a the path is now divided into two different paths. He wants to reach heaven and suddenly finds there are three persons sitting at a place. He came to know that the three people are Gandhi, Hitler and Goebbels but dont know who is who. The three people will answer only 2 questions that can be directed to any of them. Now the dead man knows Gandhi always speaks truth , Hitler always tells a lie and Goebbels tells whatever he wants. If you were to ask those 2 questions , how will you go on asking what questions that can tell you the correct way to the heaven.

Solution
How to go about it?(Hint)
Here first we need to remove the most vague and dangerous part of the puzzle i.e the Goebbels , who can tell anything a lie or a truth. So the first question must eliminate this guy for sure.

Now that we know the remaining two persons either always tell a lie or always tell a truth. The truth speaking person will always tell the correct way. Now the problem lies in the fact that you dont know whether the person you are asking is telling a lie or a truth. Making the use of always lying behaviour you must frame the second question in such a way that it negates itself twice and returns back to the correct answer.

Having being through with the strategy now lets go for the problem

Eliminate Goebbels ---> Question to ask anyone . Is A more honest than B?? If he answers Yes then ask B or else ask A the next question
Scenario 1a: Person is Gandhi , A : Goebbels , B: Hitler
Answer : Yes
Next question to : B

Scenario 1b: Person is Gandhi , A : Hitler , B:Goebbels
Answer : No
Next question to : A

Scenario 2a: Person is Hitler , A : Goebbels , B: Gandhi
Answer : Yes
Next question to : B

Scenario 2a: Person is Hitler , A : Gandhi, B: Goebbels
Answer : No
Next question to : A

Scenario : Person is Goebbels , A : Hitler , B: Gandhi
Answer : Yes / No
Next question to : B (We have already eliminated Goebbels , as we asked the question from him only)

Next Question: Am i correct to assume , when i ask you whether the way to heaven is to the left , you will respond Yes??
Now if he is Gandhi he will tell the correct way. and if Hitler he will negate the question twice to give the correct answer. First that heaven it to the left , he will try to say no its to the right. Then he will negate again and say you assume right!