This is an old puzzle, but if you haven't seen it before it should make you think.

 

You stand before two identical doors. On door leads to a long and rewarding life, the other door leads to sudden death.

Before each door is a guardian who, if you ask him the correct question will tell you which door to take.

However one guardian always lies and the other always tells the truth. You don't know which one lies.

You are only allowed one question. You walk up to a guardian and ask him the one question you are allowed and he tells you which door to take.

What is your question?

"What would the other guardian's answer be to the question 'What door would leads to a long and rewarding life'?"

"What would the other guardian's answer be to the question 'What door would leads to a long and rewarding life'?"

Would you take that door?

No. You take the other door.

 

If you can only take the door that the guardian answers with, you need to ask "What would the other guardian's answer be to the question 'What door would leads to sudden death'?"

No. You take the other door.

 

If you can only take the door that the guardian answers with, you need to ask "What would the other guardian's answer be to the question 'What door would leads to sudden death'?"

 

I may be wrong here but i would ask the guardian to reveal whats behind the door he guards. And see for you'r self. If not than i suppose i would ask the guard what door would lead me to hell and then take the oppisite door. so if hes telling the truth i avoid death and if hes lieng i still pick the oppisite and live. Am i right?

No, you have one question and must go through the door you chose. - you can't have a look and change your mind.

so you ask the guard, what door would the other guard say is the door of death. Then take the oppisite door, either way should lead you to the door of life..

 

 

.

 

so you ask the guard, what door would the other guard say is the door of death. Then take the oppisite door, either way should lead you to the door of life..

You just died! But you are on the right track.

Edited January 11, 201115 yr by TonyMcC

.

 

 

You just died! But you are on the right track.

 

Sure about that?

 

Anyway.

Push both guards through their respective doors. Go through the door without screams.

Sure about that?

 

Anyway.

Push both guards through their respective doors. Go through the door without screams.

 

Ask either guard which door the other guard says leads to sudden death. Take that door (not the opposite door).

 

I forgot to tell you the two guards were sumo wrestlers armed with machine guns lol.

Edited January 11, 201115 yr by TonyMcC

would you just ask the gaurd

if he/she was a

gaurd and the one that

lies would say no

would he/she not?

 

 

would you just ask the gaurd

if he/she was a

gaurd and the one that

lies would say no

would he/she not?

That is one question - You are not allowed another question. Knowing which guard lies doesn't help you.

Does anyone know why this makes me think of the phrase "Ugh! I hate beer"?

Does anyone know why this makes me think of the phrase "Ugh! I hate beer"?

 

Maybe one time you got drunk off of a few bud-lights, were captured by an evil overlord with access to sumo wrestlers with M16s, a penchant for thought games, a door that was capable of killing anyone that passes through it, and its not-as-cool-as-the-death-door-twin, and escaped?

Edited February 8, 201114 yr by A Tripolation

I would pretend that I am Lord Voldemort. I bet they won't dare telling lie.

 

I would pretend that I am Lord Voldemort. I bet they won't dare telling lie.

Go through both doors in superposition. Collapse the wavefunction of whichever reality is nicer.

I just went up to one of the guards and asked him if the other guard believed any of the alternative solutions would work and he said "Yes, all of them". lol

I just went up to one of the guards and asked him if the other guard would say that he believed any of the alternative solutions would work and he said "Yes, all of them". lol

Edited July 24, 201114 yr by TonyMcC

For a slightly stricter question:

 

Assume you in fact only have one guard, not two. This guard either always tells the truth or always lies. What question could you ask him to find out which door to take?

=Uncool-

if you go against your nature would you recommend going through this door if I wanted a nice continued life? - and do opposite

if you go against your nature would you recommend going through this door if I wanted a nice continued life? - and do opposite

Heh. That's a little more convoluted than necessary. Can you figure out a simpler question?

=Uncool-

but being less convoluted would be going against my nature! I will give it some more thought...

Simple .. you ask one to ask his friend About the wrong answer .. in any order, it'll be a lie .. it's most similar to Logic Gates.

 

Trying to identify the liar among them is also easy, after knowing the "truth", you simply ask one of them.

The case of a single guard ( two doors ,one question ) is similar. Ask 'which door would a lier recommend I take', then take the opposite.