Is the Guard from Heaven or Hell?

[dipinsingh]

You found a guard right between Heaven and Hell ( you don't know which is which). He is from one of them and you don't know which of them he is from. If he is from Hell, he always lies and if he is from Heaven, he always speaks truth.
You got to find out heaven asking him only one question.

What would be your question?

 

[humanino]

I'm not completely sure, I would try

Spoiler

"Is the door leading to the place you come from on the left ?"

• If he comes from Heaven
  • if Heaven is on the left, he will say yes
  • if Heaven is on the right, he will say no
• If he comes from Hell
  • if Heaven is on the left, he will say yes
  • if Heaven is on the right, he will say no

So independently of whether he comes from Heaven or Hell, Heaven is on the right if and only if he says "yes".

 

[dipinsingh]

I'm not completely sure, I would try

Spoiler

"Is the door leading to the place you come from on the left ?"

• If he comes from Heaven
  • if Heaven is on the left, he will say yes
  • if Heaven is on the right, he will say no
• If he comes from Hell
  • if Heaven is on the left, he will say yes
  • if Heaven is on the right, he will say no

So independently of whether he comes from Heaven or Hell, Heaven is on the right if and only if he says "yes".

Your answer is correct.
just ask him ... which door u belong to...?

 

[LogicNoob]

Spoiler

So independently of whether he comes from Heaven or Hell, Heaven is on the right if and only if he says "yes".

Shouldn't this mean that heaven is on the left only if he says "yes"?

 

[The riddler]

I'D ask him can you say no. If he says no, he must be from hell.

 

[llauren84]

Shouldn't this mean that heaven is on the left only if he says "yes"?

You're right.

 

[junglebeast]

I'm not completely sure, I would try

Spoiler

"Is the door leading to the place you come from on the left ?"

• If he comes from Heaven
  • if Heaven is on the left, he will say yes
  • if Heaven is on the right, he will say no
• If he comes from Hell
  • if Heaven is on the left, he will say yes
  • if Heaven is on the right, he will say no

So independently of whether he comes from Heaven or Hell, Heaven is on the right if and only if he says "yes".

I wonder if there is a way to generalize this logic to get truthful answers out of someone you are questioning (in real life) regardless of whether they are being honest or dishonest with you

Unfortunately I am terrible with these kinds of riddles, so I'm not sure...

 

[Russell Berty]

Why don't you try the harder version?

https://www.physicsforums.com/showthread.php?t=310984

 

[peeyush_ali]

Ask him whether he is a male or a female ..if he says female ..then you can confirm that he is from the hell and u may know the which is whcih ...if he's from heaven he would say "im a male" and subsequently u would know which is which... ;)

 

[peeyush_ali]

oh sorry..the condition you have given is to ask "one question"..i didnt noticed it

 

[turbo]

Just ask "would someone from your place say that this is the direction to heaven?"

 

[thrill3rnit3]

Ask him "Where are you from"

If he's from Heaven, he's going to tell you the truth - points to Heaven
If he's from Hell, he's going to lie - points to Heaven

:)