Does anyone know the answer to this riddle?

Option C – You open a door, throw the man through to the other side, and if you then hear screaming and combustion, go through the other door.

This sounds like the two doors and two guards riddle that I’ve heard before. One guard always tells the truth the other always lies, you don’t know which guard is which, what do you ask? In which case the answer is to ask either guard which door would the other guard say leads to the fulfilling life and then take the opposite door.

Perhaps your friend worded it wrong?

No. He was very clear that there was only one man. You have to determine somehow that he is trustworthy, and get him to tell you which door is the correct one.

And you can’t touch him.

If the man isn’t trustworthy, does that mean he always lies ?

Anyway I have no idea of the answer, but maybe you could show him a door and then ask him : “Will you tell me this door leads to damnation ?”...

I’m too tired to think about it seriously, but something like that might work…

Could you say something like: “You, sir, are coming with me; so which door shall we go through?”
Because then it doesn’t matter if he’s trustworthy or not? He wants to go to the fulfulling life avoid the damning one too?

Well, I got an answer from my brother here. It only establishes if he tells the truth.

“If I open Door A, are my chances of happiness 50 percent?”

Only problem is that it doesn’t give you an answer to which door you should choose.

How about asking him which door he would go through given the choice?

That’s what I was thinking. “If the chance of happiness is 50 percent, would you go through door A?”

Problem is, it doesn’t establish trust. It removes it, since you gave him the 50 percent.

why not just sit and wait for him to go into a door… besides what is so bad about damnation…Its for people who like doing the things that get one put in damnation… a party every night… : )

I think this is the answer:

Would it be a lie if I said that you would say the door on the right leads to death and damnation?

IF THE DOOR ON THE RIGHT LEADS TO D&D -

- if the person is truthful, they would say that it does lead to D&D. Therefore, it would not be a lie. And the person would, being truthful, answer “No.”

- if the person is a liar, then they would say that it doesn’t lead to D&D. Therefore, it would be a lie. But since the person would lie about that, the answer would also be “No.”

IF THE DOOR ON THE RIGHT LEADS TO FULFILLING LIFE -

- if the person is truthful, then they would not say that the door on the right leads to D&D. Therefore, it would be a lie to say that he would, and therefore answer “Yes.”

- if the person is a liar, then they would say say that the door leads to D&D. Therefore, it would not be a lie to say that they would say it. Again, however, since they would lie about it being a lie, the person would answer “Yes.”

Therefore, in either case, if the person answers no, you know in any case that you should take the door on the left. If the person answers yes, you know in either case that you should take the door on the right.

That’s when you become a nihilist and just march through one door or the other, either way it doesn’t matter. =D

I think you got it…I’ll reply if it’s right.

@iamthemob I’m impressed. Now we just have to hope this person can follow the logic well enough to answer according to his character.

@iamthemob I think you got turned around by one too many double-negatives.

According to your first statement which I can hardly bear to read, it’s so convoluted Would it be a lie if I said that you would say the door on the right leads to death and damnation?

You said that if the door does lead to D&D, then the truthful person would say that it is not a lie… but it would be. I’m not taking the analysis any further; it hurts my head just to read it all. (But it was a nice try.)

There is no way to resolve both conditions with one question. You cannot determine with a single question to a teller whose veracity is ‘questionable’ whether or not you want to go through Door A or Door B.

The other thing that I’d say is that both doors do lead to death, in any case, so you may as well just tell that dude to get out of you fecking way, because you choose… whichever.

Exactly what I was thinking @CyanoticWasp, that’s why it doesn’t work because either way you cannot determine if the person is telling the truth or lying. That’s why I really believe it’s the riddle with the two men and the friend just remembered it and told it wrong. It happens, I know I’ve done it before.

Yep, @HearTheSilence, that one is a classic, and you had that answer.

@CyanoticWasp

You said that if the door does lead to D&D, then the truthful person would say that it is not a lie… but it would be.

Unfortunately it’s convoluted because it has to be. The question is “Would it be a lie if I said [that you would say it’s the door on the right]?” Now, if I’m saying that you said that the door on the right leads to D&D, then the answer is no – it’s not a lie. I would be saying something accurate. Therefore, if you only speak the truth, you would tell me no, it’s not a lie. However, if you would say that it is not the door on the right, then yes – it is a lie to say that you would say it’s the door on the right. And if you lie, you would tell me the opposite of that – no, it’s not a lie.

Now, I’m not certain, but that seems to work. Does that clear it up for you…or do you still disagree…

@HearTheSilence – I thought so at first as well…but this does seem to be a separate riddle.

With the original riddle of two guards, the answer is always predictable when their answers are combined (take the opposite), because the combination the truth and its’ opposite (a lie) is always the opposite (a lie), (one guard must lie, one guard cannot…therefore in combination….you get a lie)..like multiplying a negative by a positive number, always gives a negative number.

I think you (iamthemob) are trying to become the missing “guard” in your example, and thus get to the same result. But it doesn’t work because you always end up asking a question of someone who may or may not be answering truthfully (they could be “guard lie” or “guard truth”). In other words, even if you are truthful (to yourself), they may or may not be, thus doing the opposite or the same as what they say doesn’t help (no matter how many convultions you hurt my head with). :)

I’d love to wrong on this, but I don’t think I am….

but I could also be lying

“convultion” – Convulsions caused by convoluted sentences..

@AdamF – That’s very much what I tried to do. But I don’t think I’m wrong based on what you post, as I think that you’re working with a few too many “real world” assumptions in relation to the riddle.

My answer is set up to produce the same answer whether or not the guard is the liar or the truth-speaker. And it depends only on an objective, black and white assessment of the truth or the lie.

The question only takes into account (1) that one of the doors is the right answer, (2) the guard always lies or always tells the truth, (3) that black and white analysis means that there are simple on/off logic switches, and (4) any statement regarding the door or about statements about the door by extrapolation are yes/no, true/false, and therefore a lie or the truth.

So, if the door on the left leads to D&D, if asked if the door on the left leads to D&D, T will say the door on the left leads to D&D, and L will say the door on the right leads to D&D.

It may be more simply stated, actually, but it’s necessary to make them answer a question about how they would answer. So, asking “Would you say yes if you were asked if the door on the left leads to D&D,” T answers yes, because the door leads to D&D, and L would answer yes, because he would not say yes, so he must lie about what he would say. If, however, it’s the door on the right that leads to D&D, T would say no, because it is not the truth, and therefore he would not say it. L, being asked if the door on the left leads to D&D, would answer “yes” if in fact the door on the right lead to D&D, so asked what he would say would have to answer “no.”

So, a simpler, cleaner version is Would you say “yes” if asked if the door on the left leads to D&D.

If LEFT door leads to D&D:

If the speaker is truthful (T), then if asked if the door on the left leads to D&D, he would answer “yes” because that is the truth. Therefore, he must answer “yes” regarding whether he would say yes that the door on the left leads to D&D because that is the truth about what he would say.

If the speaker is a liar (L), then if asked if the door on the left leads to D&D, he would answer “no” because that is a lie. Therefore, he must answer “yes” regarding whether he would say yes that the door on the left leads to D&D because that is a lie about what he would say.

And therefore, if the answer is “yes,” I know not to go through the door on the left as that is the one that leads to D&D, regardless of whether the person is being truthful or being a liar.

If RIGHT leads to D&D:

If the speaker is T, then if asked if the door on the left leads to D&D, he would answer “no” because it would be a lie to say yes. Therefore, he must answer “no” regarding whether he would say yes that the door on the left leads to D&D because that is the truth about what he would say.

If the speaker is L, then if asked if the door on the left leads to D&D, he would answer “yes” because it is a lie that the door on the left leads to D&D. Therefore, he must answer “no” regarding whether he would say yes that the door on the left leads to D&D, because that is a lie about what he would say.

And therefore, if the answer is “no,” I know not to go through the door on the right as that is the one that leads to D&D, regardless of whether the person is being truthful or being a liar.

@iamthemob The second example works, but the first doesn’t.

@chocolatechip – how does it not work? I may not be seeing it because, although each choice is just yes/no…there are a few. But I still think both work…where does the matrix fail?

@iamthemob Yes, but where does it say that the white robbed man “always” lies or always tells the truth? A dishonest man may intentionally mislead you or intentionally try to confuse you by being honest. There is no obligation to answer either way, once you ask “would you…” it’s back to square one.

I’ve gotta have lunch…I love reading your response regardless..and as I said, I hope I’m wrong on this as it would be a fascinating piece of logic to get an answer to this riddle.

@iamthemob

Would it be a lie if I said that you would say the door on the right leads to death and damnation?

If the door on the right leads to death and damnation, and the liar says the door on the right leads to death and damnation, this statemet would be the truth. You ask if the statement a lie. It is not a lie, but the liar will tell you that it is, therefore, “Yes”.

Thus, if the door on the right leads to death and damnation, the truth teller will answer no and the liar will answer yes. Inconclusive.

@AdamF – You’re 100% correct that that’s not how it’s written. However, the other permutations of it make it more clear…and also, I mean, again – it’s a riddle, not the real world. Giving people personality traits that are reflective of how real people act in the real world introduces all the variables of people that make a logic riddle more of an analysis of the human psyche. But if the OP didn’t intend to make trustworthiness an absolute characteristic, we’ll go with another method.

Would you tell me that someone who told the truth 100% of the time would say “yes” if asked if the door on the left leads to D&D?

If LEFT door leads to D&D:

If the speaker is truthful (T), then if asked if this person would say the door on the left leads to D&D, he would answer “yes” because that person would say the truth. Therefore, he must answer “yes” regarding whether he would say that the person would say yes that the door on the left leads to D&D because that is the truth about what he would say. Because he is honest about what he would claim an honest man would say, it’s yes.

If the speaker is a liar (L), then he would say that someone who told the truth 100% of the time would answer “no” if asked if the door on the left lead to D&D, because that would be a lie about what that person would say. But if he says “no,” he’d be telling the truth about what he would say, so he has to say “yes.” Because he’s dishonest about the fact that he would say an honest man would give the wrong answer, he claims he would say the honest man would say yes.

And therefore, if the answer is “yes,” I know not to go through the door on the left as that is the one that leads to D&D, regardless of whether the person is being truthful or being a liar.

If RIGHT leads to D&D:

If the speaker is T, then if asked if this person would say the door on the left leads to D&D, he would answer “no” because that person would say the truth. Therefore, he must answer “no” regarding whether he would say that the person would say yes that the door on the left leads to D&D because that is the truth about what he would say. Because he would claim that an honest man would not state this if it was a lie, the answer is no.

If the speaker is a L, then he would say that someone who told the truth 100% of the time would answer “yes” if asked if the door on the left lead to D&D, because that would be a lie about what that person would say. But if he says “yes,” he’d be telling the truth about what he would say, so he has to say “no.” Because he would claim that an honest man would say that you should go through the left door if the right door was the right answer, being dishonest he would say that’s what he wouldn’t do – and therefore, he answer is also no.

And therefore, if the answer is “no,” I know not to go through the door on the right as that is the one that leads to D&D, regardless of whether the person is being truthful or being a liar.

I think that’s a little better, more “in the moment.”

Nevermind

If the door on the right leads to death and damnation, and the liar says the door on the right leads to death and damnation, this sentence would be the truth. However, you ask if the sentence is a lie. It is NOT a lie, but the liar will tell you that it is, therefore, “Yes”.

The problem is, of course, that if the person is not trustworthy, he will always give the opposite answer of the one he would give if he was trustworthy, or the opposite representation of the truth. So, if the person is untrustworthy, and they know that the door on the right leads to D&D, they wouldn’t say that it did. They’d say that the door on the left did. So, indeed, it would be a lie if I said that, if it’s the truth, they’d tell the truth. But the untrustworthy person would claim, since it is a lie that if the door on the right actually did lead to D&D that’s what they would say, that it was not a lie. So, the answer is still no.

Thus, if the door on the right leads to death and damnation, the truth teller will answer no and the liar will answer yes. Inconclusive.

I think that they both say no.

As to the assumption – I don’t really assume an answer any more or less in any of them. It’s just that in the first and third I ask if the answer they give is a lie or is something someone who couldn’t lie would say. All three assume an answer of “yes” in the question, but don’t say if that’s right.

@chocolatechip – So by nevermind you’re agreeing that it all works out…right? The extra set of eyes helps.

@iamthemob

No, your second example is still incorrect for the reasons given above, but that’s irrelevant seeing as how you’ve got the answer. I was going to say that your third example was also incorrect, but I realized I misread part of it, so I edited my post.

A riddle has to follow its own rules, and if we add our own, then we are no longer solving the riddle. We can’t add “the liar must always lie”, without changing the rules of the riddle. So this isn’t an issue of me making real world assumptions, its an issue of following the rules as provided by the riddle.

Anyways, let’s assume regardless that we add the extra factor to the riddle, and the liar must lie. Even here the solution you present has a problem because the answer to your question can be lied to at two levels

The liar can be honest about their lying (assume left = D&D)

“Would you tell me that someone who told the truth 100% of the time would say “yes” if asked if the door on the left leads to D&D?”

L=No

But you say they can’t do that because that would be telling the truth about their lying. So you say they have to answer yes. But as the “yes” answer itself is infact also truthful (yes is the answer given by the truthful guy), one could argue that they are infact breaking the rules set for them by you (ie they must lie), and cannot provide the same answer as someone who is telling the truth. Hence they must say No. Once that happens, game over. But admitedly, we are both imagining the unwritten rules of this riddle world…

Okay so in case Im wrong, let’s pretend anyways that they must conveniently say “yes” to this question.

But unfortunately the question has two parts, so another problem arises.

“Would you tell me…” is the first part. He could lie to that, and lie that he wouldn’t tell you an answer at all. Hence he could say “No” again, and you wouldn’t know what question he was in fact answering…ie By asking if he “would tell you”, a liar can answer no, and meet your requirements to always lie.

And once you can get a no or yes answer…to any issue raised above, then it’s back to square one, unfortunately.

@AdamF You can’t answer this question without reducing certain variables to absolutes. Just like any kind of word problem, you must assume certain things. If I give you a simple math problem such as, “Sara has 4 pennies. Sam gives her 5 pennies. How many pennies does Sara have?” Obviously the answer is 9. You can’t be expected to account for every possible variable, like “Does anybody else give her pennies? Does she lose any of the pennies? Does she deposit the pennies in her bank and gain interest on those pennies? What about other pennies that she had prior to the transaction?”

This is why these kinds of riddles are stupid in the first place.

@chocolatechip I don’t think the pennies analogy is a fair comparison for what I am doing. Your example is clear cut (4 and 5 pennies), and then ambiguities are supposedly added (other penny givers). In contrast, this riddle is ambiguous with respect to what the liar does and does not do, and how often they do it. and then simplifying rules are added to ensure consistent behaviour of the liar. As such iamthemob is adding an assumption that simplifies the original riddle.

All I am doing is pointing that out, that that is an added assumption, which makes the riddle potentially solvable, whereas the riddle as written in this post, is not.

You’ll also notice, I hope, that I’m not being anal about this, but am happy to go along for the ride with respect to these assumptions.

@chocolatechip -

I’m still not seeing how it’s wrong. If the question is “Would it be a lie if I said that you would say the door on the right leads to death and damnation?” and the right door does, here’s how it would go:

A (truthful) if asked if right=death, would say yes.
B (liar) if asked if right=death, would say no.

Therefore, we’re asking A “Would it be a lie to state you would say yes?” The answer is no. And A would say No (being truthful).

We’re asking B “Would it be a lie to state you would say yes?” The answer is yes, Because the answer is yes, B would say no (being untrustworthy).

I’m still getting no…

@AdamF -

It’s inevitable that someone who would lie all the time would be forced to claim the opposite of something claimed before. Generally, this ends up being someone lying about whether they had stated something that was a lie.

So, when we ask someone what they would say, the lie only need relates to what they would say – they only need say they would say “no” when they really would say “yes.”

So in the example you went with, left leads to D&D

“Would you tell me that someone who told the truth 100% of the time would say “yes” if asked if the door on the left leads to D&D?”

The person who tells the truth would therefore say “Yes.”

A person who lies would say that a truthful person would say “No,” however.

So, if asked what the liar would say and the liar was honest about what he would say, he would say “No.” He would say that he would lie. This, however, would be the truth.

Therefore, the answer would be “Yes.” Because we are asking him to tell us what he would say a truthful person would say. He would say the person would say “no” because it would be a lie to claim that person would say “no.” And since that’s what he really would say, he must answer yes.

It’s clear that we make certain assumptions here. Of course, if you don’t, the riddle is unsolvable. It’s not any sort of stretch, therefore, to simply imagine this is the exact same question as the two person, two doors one…but just one of the dudes has up and died.

Because we are limited to a single question, there is no riddle unless a single question can answer all you need to know to make the right choice. If one question can reveal whether this person is deceitful or truthful, it means that if the answer to that question is deceptive, then the person will always be deceitful.

Adding or considering complicated elements doesn’t make sense when you’re chances are so limited by the rules. The consequences of any and all choices need to be clear.

Knowing this, do you see problems with my reasoning?

I started answering your question about (my perception) of problems with the reasoning and realized I was just rehashing issues raised above. Essentially, that there are 1) two aspects of the question he could lie to, and 2) the degree of lying can be judged as permissable or not depending on subjective assumptions about what is and is not permissable in this riddle world (“No” is still possible as far as Im concerned, but not as far as you’re concerned). I think the divergence between us all hinges on differences in our assumptions about the riddle with respect to what degree (or levels) of lying is permitted by the liar.

That said, I do think your answer is as about as close as anyone could get to answering this unanswerable (probably misconveyed) riddle.

But now I must get back to the fulfilling life I’ve was lucky enough to pass the correct door into…

Best wishes…

@AdamF – sorry to defill.

@iamthemob You’re trying so hard to desperately rationalize your answers that all you’re doing is repeating the same thing just paraphrased differently. I get why you’re doing it, you think you’re right, but as @chocolatechip mentioned, “You can’t answer this question without reducing certain variables to absolutes.” In fact, you can’t even ask the man directly, “are you an honest man?” because you don’t know if he’s lying about that! There is no one question that you can ask the one man that will give you a definitive answer, because (again) you can’t trust his word to be honest. That’s why this riddle, worded the way it’s worded, is not a riddle at all—riddles have solutions, this (again, worded the way it is) does not.

@iamthemob

Would it be a lie if I said that you would say the door on the right leads to death and damnation? (your first example) is not the same question as “Would it be a lie to state you would say yes?” (your second example). The first question doesn’t work, the second one does.

@chocolatechip

Yes it is, though. Whether or not the person would say yes that the door on the right leads to D&D depends on whether they’re truthful or not. If in fact they are, and it would lead to D&D, they say yes. If not, and it does, they would say no. If they are honest, and it doesn’t lead to D&D, they say no. If not, and it doesn’t, they would say yes.

So, “the door on the right leads to D&D” if factually right would be a statement that the truthful person would make, and the liar wouldn’t. If it’s factually incorrect, that switches.

Now, we have the question: “Would it be a lie if I said you’d agree (say yes, whatever).” If factually correct, with the truthful person it is not a lie, they would agree. The liar would not agree, and therefore it would be a lie. The honest person says it’s not a lie because it isn’t. The liar says it’s not a lie because it is.

You have to think of “would you say yes” as a shortand for “would you say the door on the right leads to D&D.” These aren’t different examples, just different versions as I see it.

@iamthemob I really enjoyed the discussion, didn’t mean to imply otherwise

@AdamF – ;-)

@iamthemob

No, this is incorrect. The exact wording is important. I know this is completely trivial, but here I go.

They are not the same question. The distinction is that the first question asks if the man is lying. You cannot determine whether someone is lying by asking if they are lying.

Assuming the door on the right leads to damnation and death:

The first question is, “would it be a lie if you said the door to the right leads to damnation and death?” Break this question into two parts: “would it be a lie if” and “you said the door to the right leads to damnation and death”. The second part of this sentence is always true. Therefore, the truthful answer to the first part is no, while the lie is yes.

The second part of the question establishes the truth, meaning the only variable is the first part which asks, “would it be a lie if TRUTH” or equivalently “are you lying about TRUTH”.

The second question on the other hand, asks “would you say yes when asked if the door on the right leads to damnation and death?” Essentially, you’re asking, “would you say TRUE about TRUTH”?

To compare,

Q1 paraphrased: “Are you lying about TRUTH?”

Q2 paraphrased: “Would you say TRUE about TRUTH”?

Hmm. It’s not completely trivial…considering that the answer requires some very specific parameters, so let’s nitpick. ;-)

The second part of the question is not fixed, though, fully. It’s important that you worded it differently than I did. Mine was “Would it be a lie if I said that you would say the door on the right leads to death and damnation?” That second “would” is the deciding factor. Whether or not the door on the right leads to D&D is inconsequential, because whatever the answer, the answer to the overall question will tell which is which.

So, if the door on the right does lead to D&D, then if telling the truth (T), the man would say that it leads to D&D, and if lying (L) the man would say that it does not lead to D&D. So, the man must determine what he would say, and is only judging whether or not he would agree with me. And because what I’m asking him to tell me is if the statement I would make about what he would say would be a lie, if T and it’s DR, he would say it’s not a lie because he would say DR because that’s the truth; and if L and it’s DR, he would say it’s not a lie because he would say it’s not DR because he would lie – but he’s going to lie about his lie, and because our answers are yes/no and focused on one door, the same answer is given by both and we know that DR leads to D&D.

Extreme shorthand:

Q1 – Would it be a lie to say you said X (where X is the answer to Q2)
Q2 – Would you say that DR = D&D

When DR = D&D

T answers Q2 yes (because it is true), and Q1 no (because it is not a lie)
L answers Q2 no (because he would say DL = D&D if in fact DR = D&D), and Q1 no (because it would be a lie to say L would answer Q2 in that manner, but L would lie and say his Q2 answer would be yes).

When DL = D&D

T answers Q2 no (because it is untrue), and Q1 yes (because it is a lie and he would say it was)
L answers Q2 yes (because he would say DR = D&D if in fact DL = D&D), and Q1 yes (because L would answer Q2 in that manner described, but that would be a lie, and L would lie that his initial answer would be “yes” and say his Q2 answer would be no).

Let’s try reversing it…“If I claimed that you would say the door on the right (DR) leads to D&D, would you agree?”

Q1 – “Would you say that DR leads to D&D?”
Q2 – “If I claimed that you would, would you agree?”

If DR leads to D&D:
Q1 – T answers yes, L answers no.
– Because T would say that, L would say the opposite.
Q2 – T answers yes, L answers yes.
– Because T agrees that this is what he would say, and would tell the truth about it. L, on the other hand, would say DR does not lead to D&D because it does. Therefore, in truth he would disagree that he would say that. He does not say that, but because the question is now if he would agree that it’s something that he would say, because he would disagree, he will say that he agrees. L would state that he agrees because he actually disagrees. Therefore, both would agree.

If the left door (DL) leads to D&D:
Q1 – T answers no, L answers yes.
– Because T would say that it doesn’t, L would say the opposite.
Q2 – T answers no, L answers no.
– Because T disagrees that this is what he would say, and states the truth that no, he would not agree because he would not tell a lie. L, on the other hand, would say DR does lead to D&D because it does not. Therefore, in truth he would agree that he would say that. Because the question is now if he would agree that it’s something that he would say, and because he would agree, he will say that he no, he does not agree. Therefore, both would disagree.

And in true anal form, a graph!

Answers to Q2 (original above) – “Would you say that DR = D&D?

T – states truth, L = states lies, Y = Answers Yes, N = Answers No, DL = D&D means Left Door is D&D, DR = D&D means Right Door is D&D.

************************************
Door..I DR = D&D I DL = D&D I
************************************
T . . ..I . . . . Y . . .I . . . .N . . ..I – - Both the truth
************************************
L . . . I . . . . N . . .I. . . . Y . . ..I – - Both a lie
************************************

Now, Q1 – Would it be a lie to state your answer to Q2 would be yes?

************************************
Door..I DR = D&D I DL = D&D I
************************************
T . . ..I . . . . N . . .I . . . .Y . . ..I – - (States that it is not a lie when DR = D&D, so
************************************ – - – the statement DR = D&D is true and I go
L . . . I . . . . N . . .I. . . . Y . . ..I – - – through DL. States that it is a lie when DL
************************************ – - – = D&D, so I go through DR).

Ladies and gentlemen, @iamthemob is correct. My friend confirmed (finally) just today. GOOD JOB!

Ah then the answer is that there is no answer! Awesome riddle. sarcasm

@HearTheSilence – Don’t hate…;-)