The door riddle
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Arkoth — 11 years ago(March 08, 2015 05:56 PM)
So.. say she asks the guy in the left. The guy in the left tells her the door that leads to certain death is the left door.
Then what? You still can't tell who's lying and who isn't.
If the guy in the left is telling the truth then she should go to the right.
If the guy in the left isn't telling the truth then should go to the left.
Well you're fvcked then.
You
have
to make the question filter through both goblins because then you know that it will ALWAYS BE A LIE, since the truth teller will tell the other's lie, and the liar will lie about the other's truth. -
CapnKaos — 11 years ago(March 21, 2015 11:49 PM)
No you don't. You just need to pose the right question to the right person.
One guard always lies, one always tells the truth. You'll never know which is which but they allow you to ask one question to one guard. And knowing that you can then work it out.
If you ask either guard which door leads to freedom he will point to one of the two doors. The one that tells the truth will tell you the truth and the one that lies will lie. So no help there. But if you ask the guard what door the other one would choose then you know
not
to chose that door.
For example, you ask Guard A which door would Guard B say leads to freedom? He will point to one of the doors. Now, if Guard A is a liar then he will never point to the actual door but instead will lie and point to the other one. However if you ask Guard B who only tells the truth he will honestly point to the door that Guard A would choose.
You can then safely choose the door they
didn't
point to. Or at least that's how it's supposed to go. I don't remember how they phrased it in the movie but I would think it's similar to that.
It reminds me of a similar puzzle. You're a foreigner traveling in foreign lands and in this land are two peoples. One group are the Slobovians who only tell lies and can't be trusted. The other group are the Archons that only tell the truth and can be trusted.
You're paddling along in your canoe and see three people standing on a dock. Not wanting to tie up your canoe where a bunch of Slobivians might steal it you call out, "are you Slobovians or Archons?"
The first one responds but his words are carried away in the wind. You call out again and the second one responds saying, "he says he's an Archon and he
is
an Archon and so am I".
The third one calls out, "they're lying to you! They're Slobovians but I'm an Archon!"
Who's who?
The answer is simple. The first two are Archons and the third one is a Slobivian. How did we come to that conclusion?
If asked, either group will answer that they're Archons. An Archon will tell the truth and a Slobovian will lie. So regardless of what the first one said we know that the second one repeated and confirmed what the first one said thus he too is an Archon. Had he been a Slobovian he would have said that the first one said he was a Slobovian but he is an Archon.
As we know the first two are Archons, the third one is then a Slobovian and it's safe to tie up your canoe there. -
kb541 — 10 years ago(April 25, 2015 08:16 PM)
I still can't wrap my brain around this riddle. The nearest I can get to some kind of understanding is the phrasing of the question is the key to getting the true answer. Not asking, what's the right door? Instead asking, Which door would the other guy say is the right door?
Is that at least partway correct? That's as far as I get in understanding. After that I'm totally lost. -
CapnKaos — 10 years ago(April 26, 2015 08:11 PM)
The nearest I can get to some kind of understanding is the phrasing of the question is the key to getting the true answer.
And this is exactly it. It's not that difficult once you think about it.
Instead asking, Which door would the other guy say is the right door?
Right. And then you pick the
other
door. This question always leads you that way because no matter which door is the door to freedom, the answer to your question when phrased like this will always be the door to certain death.
Let's say Door A leads to certain death and Door B leads to freedom. You turn to Guard A and ask him, "what door would your friend say leads to freedom". It doesn't matter if Guard A is a liar or not, he will always point to the door leading to certain death which in this case is Door A. Think about it. If he's a liar, then what door would have Guard B have told you to take? Guard B would say to take Door B but since Guard A is a liar he
lies
and points to Door A.
Same goes for if Guard A only tells the truth. If you were to ask Guard B which door leads to freedom, he would
lie
and again point to Door A. Guard A has told you the truth as to which door the liar would tell you to take. So again you can choose Door B.
Make more sense now? -
Weber4278 — 10 years ago(April 26, 2015 08:30 PM)
I'll try to explain it as easy as possible:
If you ask the liar which door the truthful guard would say leads to the castle, he'd lie and give you the wrong one.
If you ask the truthful guard what door the liar would say leads to the castle, he'd truthfully tell you what the liar would saywhich is a lie.
So no matter what guard you ask (liar or truthful) they'd both give you the lie by default IF you ask them what the other one would say.
Hope this makes sense. -
DrSleepandMrMercedes — 10 years ago(April 26, 2015 09:30 PM)
Both are liars. Neither door leads out of the labyrinth. If Sarah asked the Blue Guard the same question as she asked the Red Guard in the film, he would have said the same thing. I do not know how to simplify the answer, but pretend you are in the film and you asked the guards the same question. Who would you believe, the liar, or the one who only wants you to think the other is a liar to make it appear that they are the truth teller? I hope this makes sense, sorry if it doesn't.
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hurricanehorton — 10 years ago(June 26, 2015 03:49 AM)
That's the easiest way of looking at it, the way Sarah phrases it
guarantees
that the answer she is given is a lie.
If she asks the guy who is telling the truth what the liar would say, he will repeat the lie. Because that is honestly the answer the liar would give.
If she asks the guy who is lying what the honest door would say, he'd lie and say the opposite.
Either way the answer given is a lie, and she must chose the other door. -
mjn-seifer — 10 years ago(July 13, 2015 06:07 AM)
The door she took is the door to the castle. She fell in a hole because it was simply another obstacle, and only ended up in the oubliette because she chose to go down. Had she asked the hands to take her back up, and out of the hole, she would have been able to keep going. There was only one liar, and she had the correct path - they never said that there would be no traps or anything, Sarah did not ask that. Also, the oubliette was not "certain death" because the hands gave her a choice, so she still had a chance to avoid it, and if she had known to step over that part she could have avoided it herself.
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fiatlux-1 — 10 years ago(January 11, 2016 08:55 AM)
The door she took is the door to the castle. She fell in a hole because it was simply another obstacle, and only ended up in the oubliette because she chose to go down. Had she asked the hands to take her back up, and out of the hole, she would have been able to keep going. T
Exactly!!!! That was what I always thought too!!!!
That Sarah did NOT make the wrong choice, she made the correct one!
Her error was (inexplicably) choosing to go Down instead of Up.
But even in a way, choosing Down was the right way.since Hoggle was already assigned to get her out of there.
If the Oubliette was only meant to be a trap with no end, why did Jareth send Hoggle there to find her? Jareth could have just left Sarah there.
There had to be some way out that Sarah could have found.
I'd say this cloud is Cumulo Nimbus.
Didn't he discover America?
Penfold, shush. -
samhmd-7489 — 10 years ago(June 27, 2015 09:50 AM)
The best question is to just ask "Okay, what would the other door say if I asked which way to go?"
Reasoning: If the honest door answers, he'll say "Well, the other guy would've lied to you."
If he's the one that lies, then he'll say "Take this way." which clearly is the one you DON'T want to go through. -
Pandoraa — 10 years ago(August 27, 2015 11:32 PM)
Gys, guys. All this assumes that 'one of them always tells the truth and one of them always lies'.
Sarah's mistake was in taking the veracity of that statement for granted. If what the goblin said was true, than he just outed himself as the truthful one. If it wasn't true, she may as well have flipped a coin.
I suppose a smaller-caliber gun would have to fire baby teeth.