[Guest]

A man is trapped in a room with 2 indistinguishable doors, each with a guard standing in front of the door. One door will lead to death and the other will lead to freedom One of the guards will always tell the truth, the other will always lie. The man is allowed to ask each guard 1 question, however the man must ask both guards the same question. What is the question the man asks and how does he interpret the results to decide which door leads to freedom? Once the man makes his decision, he is allowed to leave with no resistance.

He does not ask a question like "Is this the door to freedom?"

[WitchOfDoubt]

Ask each guard:

"Are you going to answer in the negative or follow all of my orders from this point on, (where or also includes the case where you do both)?"

Lying guard will simply say yes.

Truthful guard cannot answer in the negative, so they must say yes. And so they must follow all the man's orders.

Then they can say, "Lead me through the correct door, give me all your money, build me a shrine," etc.

I wonder if there is a solution that gets the man two slaves instead of one?

Edited December 12, 2011 by WitchOfDoubt

[Guest]

Will you please open the door?

The man takes a look outside and exits through door to freedom.

Edited December 12, 2011 by lenzvlt

[Morningstar]

Will you please open the door?

The man takes a look outside and exits through door to freedom.

That isn't really a question with an answer, so the answer can't be either true or false.

[Guest]

Its the old question of:

"If I asked the other guard which door leads to freedom, what would he say?"

Only need to ask one guard

Always take the other door.

Edited December 12, 2011 by TheRogue

[wolfgang]

Its the old question of:

"If I asked the other guard which door leads to freedom, what would he say?"

Only need to ask one guard

Always take the other door.

I agree with "The Rogue"

[Guest]

Its the old question of:

"If I asked the other guard which door leads to freedom, what would he say?"

Only need to ask one guard

Always take the other door.

But nowhere it is mentioned in question that the guards know which door they are guarding.

[Guest]

Its the old question of:

"If I asked the other guard which door leads to freedom, what would he say?"

Only need to ask one guard

Always take the other door.

That is the correct answer.

Ask each guard:

"Are you going to answer in the negative or follow all of my orders from this point on, (where or also includes the case where you do both)?"

Lying guard will simply say yes.

Truthful guard cannot answer in the negative, so they must say yes. And so they must follow all the man's orders.

Then they can say, "Lead me through the correct door, give me all your money, build me a shrine," etc.

I wonder if there is a solution that gets the man two slaves instead of one?

Sorry, that can't work because you speak to a guard twice

Edited December 13, 2011 by Eddie Bentall

[Guest]

Man will ask:

If I ask the other guard that which is the gate for freedom, then what answer I ll receive?

[Guest]

will he tell me that his door leads to freedom?

If #1 answers yes and is telling the truth then #2s door does not lead to freedom because he would have to say yes and be lying.

If #1 answers yes and is lying then #2 would have to answer no and be telling the truth, so #1 again leads to freedom. Note you never ask #2 the question all of this is based on what the first guy says whether he is lying or not.

[Morningstar]

But nowhere it is mentioned in question that the guards know which door they are guarding.

If they don't know which door they are guarding, I believe there is no way of solving it. I'm pretty sure this has been posted before.

[Guest]

i'll ask only 1 question to one of the guards:

what would the other guard answer if i asked him which one is the door to freedom

And i'll choose the other door

[Guest]

Ajit, nowhere it is mentioned that the guards know about the honesty or otherwise of the other guard.

[Guest]

Are you both liers.

[Guest]

[its the old question of:

"If I asked the other guard which door leads to freedom, what would he say?"

Only need to ask one guard

Always take the other door.]

You said that this is the right answer but I disagree. The Rouge said 'Always take the other door' but you never mentioned the answer. It all depends on the guards answer! Otherwise you might aswell not bother asking the question. I know that that is the right aswer but I think you missed out an important fact. My answer is...

You ask: "If I were to ask the other guard if his door leads to Freedom what would his answer be?"

If the liar guards freedom and the truther guards death and you question the liar his answer would be : "Yes" (coz the truther would say no but the liar lies about this)

If the liar guards death and the truther guards freedom and you question the liar his answer would be : "No" (coz the truther would say yes but the liar lies about this)

If the liar guards freedom and the truther guards death and you question the truther his answer would be : "No" (coz the liar lies and would say no so the truther answers no)

If the liar guards death and the truther guards freedom and you question the truther his answer would be : "Yes" (coz the liar lies and would say yes so the truther answers yes).

By looking at the possible answers and senarios you can see that if the guards answers your question yes, take his door. If he answers no, take the other guards door. Knowing this you only need to ask one guard and you don't need to figure out who is who!

[Guest]

[its the old question of:

"If I asked the other guard which door leads to freedom, what would he say?"

Only need to ask one guard

Always take the other door.]

I didn't get your solution and couldn't see how it worked but i can see now sorry!

[Guest]

After brainstorming for 1 hour, finally I understand. As they say, this is the true answer to the question:

What would the other guard say if I asked him "Which one is the door to freedom?"

This is the explanation from me. Suppose there are 2 guards; Guard A and Guard B. And you ask the question to Guard A and he says "Guard B will say 1st door."

Case 1: Guard A is lying

---------

Then Guard B would say 2nd door (freedom).

Case 2: Guard A is telling the truth

---------

Then Guard B would say 1st door, which is the false door (death). Therefore 2nd door is the correct door (freedom).