The deceiver and the angel

Ok, this isn't new but I'm sure it must be for some. Just a simple test of logic.

'You find yourself standing in a hall, there are two doorways leading out of the hall. One doorway leads to heaven and the other leads to Hell. By each door stands an identical looking guard, one only tells the truth and the other only tells lies.
You, presumably would like to enter heaven but the doors aren't marked. To make it even harder to find the right door, you are only allowed to ask one question from only one of the guards...
What is the question you must ask, to ensure you go through the right door?

 

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Tab,

Would it be too much to assume that the guard who tells the truth is guarding the door to Heaven and the liar guards the door to Hell? If this is the case, I would say that you only need to ask, "Does one of these doors lead to Heaven?", or alternatively, "Does one of these doors lead to Hell?" Since you already know the truth (given in the stated premise, "One doorway leads to heaven and the other leads to Hell"), you will know which guard tells the truth and which one lies. However, this is complicated by the fact that you never told us which guard is guarding which door. Did you intentionally omit this information?

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www.indigenousrocks.com

 

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Searcher -
You don't need to know which door each guard stands by to solve this problem; simply give the doors arbitrary labels and ask the guards with respect to those labels. For example "Is heaven behind door number 1?"

In solving this problem, you have two unknowns: which guard is which, and which door is which. So, your single question must deal with both, somehow. You cannot make the doors lead to the same place, so try to form a question to which they both must give the same answer, thereby sidestepping that half of the problem.

FyreStar

 

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Here's the answer, scroll past if you don't want to see it!

*****

You must ask one of them "would the other guard tell me that door #1 leads to heaven?". If they say yes, then you know that door #2 leads to heaven, and vice versa.

*****

 

"Where would the other guard tell me that your door leads to?"

The "good" guard (guarding the door to heaven) would answer "hell" because he/she knows that the other guard always lies (and would say hell instead of heaven) and this good guard always tells the truth. Enter this guard's door to heaven.

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The "bad" guard (guarding the door to hell) would answer "heaven" because this guard knows that the other guard always tell the truth and would answer "hell" (the truth) and this bad guard always lies. Don't enter this guard's door... It leads to hell!

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P.S.

If you knew ahead of time that they were guarding opposite doors then their respective answers would be opposite from above.



[This message has been edited by truestory (edited November 13, 1999).]

 

Skyeblue,

I believe you found the correct answer! It's the only one that makes any sense without having to know which guard is guarding which door. Great job!

 

SkyeBlue/Searcher,

That's pretty good... except now you have to know which door is designated as #1 and which is designated as #2.

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Truestory,

As Fyrestar had already pointed out, "simply give the doors arbitrary labels and ask the guards with respect to those labels".

By the way, do you still believe that Skyeblue and I are the same person? I'm just wondering why you addressed that post to both of us when she's the one who offered the final solution to the problem?

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www.indigenousrocks.com

 

Hello Searcher,

Yes, I'd agree with you if communicating the labels to the guards was within the guides of the communication "allowed" in the original conditions... As far as I understood it, the communication could consist of only one question. If other communication was allowed, I'd have a thing or two to say first.

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Tab'???

The reason I addressed both of you was because Skye gave the answer and you indicated that it was the only one that made any sense, a statement which I had reason to debate... Not because I believe you are the same person.

[This message has been edited by truestory (edited November 13, 1999).]

 

Good job . Boy am I glad I didn't submit my guess.
Daaaaaaaaaa.

 

Of course, if you watch too many testosterone-packed movies, you could always kick both doors in and pick that way.

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[This message has been edited by Oxygen (edited November 13, 1999).]

 

You cannot give the doors arbitary numbers because that would entail striking up a conversation with the guards, telling them which door is which. But you're only allowed to speak to one guard anyway and if he turns out to be the liar you'd be lost before you'd even begun.The guards are not necessarily standing by their respective doors.
You're getting warm!

 

Alright, then simply point to one of the doors when asking the question...

"Would the other guard tell me this <<point to door #1>> door leads to heaven?"

Ta-daaa!

 

Good try Skye... Sounds good, but it wouldn't work under all conditions outlined...

 

truestory -
You are making this much more complicated than it really needs to be with all of the restrictions.

Which door would the other guard direct me to if I asked him which door led to hell?

FyreStar

 

FyreStar...

I am not putting any restrictions on the given situation... tab' set the stage and posed the question (not me).

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FYRESTAR FYRESTAR FYRESTAR FYRESTAR FYRESTAR!!!
YES YES YES YES YES YES YES YES YES YES YES!!!
You got it...well done!
When you pose this question (whether you ask about the heaven door or the hell door), either guard will point to the same door and so, you will choose the other one.

 

You guys......

You could ask EITHER of them, doesn't matter which,

"Is Jesus Christ the Son of God?"

That is the ONLY question that will get you to the truth. The one who lies will say no, and the one who tells the truth will say yes.

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God loves you and so do I!

 

Lori -
Sure. Have fun picking a door in that case.

FyreStar

P.S. Sorry for the double post.

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[This message has been edited by FyreStar (edited November 15, 1999).]

 

Lori -
Sure. Have fun picking a door in that case.

FyreStar