Two guards question...

[JonM]

This one is a pretty well known logic question, but probably the hardest of its kind I've come across... I figure I'll post it incase some people don't know about it

 

 

Your in a hallway with two doors. One leads to hell, one leads to heaven. There is a guard standing by each door. One of the guards always tells the truth and the other one always lies. You have one question to ask, what will it be? (assuming you want to go to heaven)

 

Thats the all info you have...

 

 

 

Don't google it if you know any other ones that are harder than this post them up...

[cosine]

"What's 2+2?"

[JonM]

"What's 2+2?"

 

Doesnt help you get to heaven... Just tells you which one lies/tells the truth. (you don't know which guard is guarding which door)

[Cap'n Refsmmat]

"What would the other guy say, if I asked him, 'Does this door go to hell?'"

 

If he says, "He'd say 'yes'" then take it, because it's the door to heaven.

[Y-S]

^^^ what if that guard said tru?

[Cap'n Refsmmat]

It's guaranteed that he's lying, because if you ask the one that lies, he'll tell you the opposite of the truth, and if you ask the one that tells the truth, he'll tell you the opposite anyways (because that's what the other would say).

[JonM]

right!... or an easier way:

 

"Which door would the other guard say leads to hell?"

[NPK]

Anyone seen Labyrinth? The scene where she has the same problem with 2 talking doorknobs?

[Sisyphus]

I've seen that same question in kid's cartoon shows. It's probably the most common "logic problem" in the world.

 

Also, has anyone else seen The Enigma of Kaspar Hauser?