[Guest]

You have died and now you find yourself walking towards the light. On your way you come to a crossroad - well... a Y-road actually, and you instinctively know that one road leads to heaven, while the other leads to hell. There are no sign posts though.

At the crossroad you see 3 figures, and somehow you just know that one of these figures always tell the truth, another always lies, while the 3rd will answer randomly.

You are allowed 2 yes-or-no type of questions to any 2 of the 3 figures (or the same if you wish).

How can you make sure that you will choose the path to heaven?

/Uhre

[bonanova]

This puzzle is of a genre posted already, in several forms.

I suspect this one already been posted, but until I find the exact previous post, I'll leave it open.

a self referential question to determine whether one of them would say one of the other two tells the truth more often than the other of the two.

That establishes their truth values, and then just ask the truth teller what you want to know.

[Guest]

interesting riddle. very nice

[Guest]

This puzzle is of a genre posted already, in several forms.

I suspect this one already been posted, but until I find the exact previous post, I'll leave it open.

a self referential question to determine whether one of them would say one of the other two tells the truth more often than the other of the two.

That establishes their truth values, and then just ask the truth teller what you want to know.

Well, I agree that it's quite similar to other puzzles - namely the "3 gods" type of puzzle previously posted by Martini. It is, however, not the same and I was not able to find the puzzle in this variant anywhere. Maybe you can

Anyway, I am not sure I understand your suggestion, but it does not seem to be a valid solution to me. Would you care to elaborate?

/Uhre

[Guest]

Well, I agree that it's quite similar to other puzzles - namely the "3 gods" type of puzzle previously posted by Martini. It is, however, not the same and I was not able to find the puzzle in this variant anywhere. Maybe you can

Anyway, I am not sure I understand your suggestion, but it does not seem to be a valid solution to me. Would you care to elaborate?

/Uhre

he means:

you ask them questions like: are u alive? over and over, the one that answers truthfully every time is the truth teller, the one that answers falsely every time, is the liar, and the one with mixed up answers is the random dude, then u ask the truth teller which one leads to heaven. and the exact wording isn't important, the point is that this riddle, with different wording, but the same idea (one liar, truth teller, and random answer)has been posted b4, and i know i've seen this one, i think it's one of the one's Rookie posted.

Edited April 2, 2009 by UGG BUYS UGLY HOUSES!

[Guest]

he means:

you ask them questions like: are u alive? over and over, the one that answers truthfully every time is the truth teller, the one that answers falsely every time, is the liar, and the one with mixed up answers is the random dude, then u ask the truth teller which one leads to heaven. and the exact wording isn't important, the point is that this riddle, with different wording, but the same idea (one liar, truth teller, and random answer)has been posted b4, and i know i've seen this one, i think it's one of the one's Rookie posted.

Ahh... but how would this be accomplished when you can ask only 2 questions? Realise that I do not wish to gamble with my afterlife. I need to make sure I end up in heaven

Edited April 2, 2009 by uhre

[Guest]

You have died and now you find yourself walking towards the light. On your way you come to a crossroad - well... a Y-road actually, and you instinctively know that one road leads to heaven, while the other leads to hell. There are no sign posts though.

At the crossroad you see 3 figures, and somehow you just know that one of these figures always tell the truth, another always lies, while the 3rd will answer randomly.

You are allowed 2 yes-or-no type of questions to any 2 of the 3 figures (or the same if you wish).

How can you make sure that you will choose the path to heaven?

/Uhre

do we know which figure is which?

or do we only know that one of them tells the truth/lie/random - but without knowing which entity responds in which manner?

[Guest]

Can I pose one question to all three of them?

e.g: To all of you, who's standing beside you, the liar or the truth teller?

Or is it limited to just one person at a time?

I'm not sure if I worded that well. Oh well, I hope you get what I'm trying to say.

[Guest]

nevermind first question... but to be sure I am approaching this the right way,

when asking one question - do we ask it of only one person? or can we ask it of two people? - and then the second question can be asked of the same two people?

[Guest]

Ahh... but how would this be accomplished when you can ask only 2 questions? Realise that I do not wish to gamble with my afterlife. I need to make sure I end up in heaven

u text god and say, 'this is not how i was told it worked!!!', then he understands, and puts u in heaven.

[Guest]

do we know which figure is which?

or do we only know that one of them tells the truth/lie/random - but without knowing which entity responds in which manner?

We do not know which is which.

[Guest]

Can I pose one question to all three of them?

e.g: To all of you, who's standing beside you, the liar or the truth teller?

Or is it limited to just one person at a time?

I'm not sure if I worded that well. Oh well, I hope you get what I'm trying to say.

No, you can only ask one question to one person, and the other question to one other (or the same) person.

[preflop]

Ive been thinking about this for a little while

I think we need to eliminate the random answerer with the first question so that the second question is posed to either the liar or the truth teller (you don't care which). That way we reduce riddle to the old Liar/Honest person/1 question/2 doors riddle.

So along that line we need a question that we could pose to either a truth teller, liar, or someone who answers randomly and get all of them to answer in a way that we know that a specific person is either the liar or the truth teller.

does any of this make sense, and am i barking up the right tree?

[Guest]

Ive been thinking about this for a little while

I think we need to eliminate the random answerer with the first question so that the second question is posed to either the liar or the truth teller (you don't care which). That way we reduce riddle to the old Liar/Honest person/1 question/2 doors riddle.

So along that line we need a question that we could pose to either a truth teller, liar, or someone who answers randomly and get all of them to answer in a way that we know that a specific person is either the liar or the truth teller.

does any of this make sense, and am i barking up the right tree?

Let's just say that I like your way of thinking

[preflop]

Okay I have an idea

Ask A: "Will B tell me the left path leads to heaven?"

If A is the truth teller he will answer like this

B=Liar: Yes or No (i don't care which)

B=Random: No answer because he does not know and therefore unable to tell the truth.

If A is the liar he will answer like this.

B=Truth: Yes or No (i don't care which)

B=Random: No answer because he does not know and therefore unable to tell a lie.

If A is the random answerer he will answer like this.

B=Truth: Yes or No

B=Liar: Yes or No

So If i get an answer I can safely assume B is either a liar or a truth teller, if I do not get an answer then C is either a liar or a truth teller.

based on that I will ask either B or C (the one I know not to be the random answerer).

"Would you tell me the Left path leads to Heaven if I asked you?" If he answers Yes - it is the path, if he answers No, the right path is the correct path.

[Guest]

Okay I have an idea

Ask A: "Will B tell me the left path leads to heaven?"

If A is the truth teller he will answer like this

B=Liar: Yes or No (i don't care which)

B=Random: No answer because he does not know and therefore unable to tell the truth.

If A is the liar he will answer like this.

B=Truth: Yes or No (i don't care which)

B=Random: No answer because he does not know and therefore unable to tell a lie.

If A is the random answerer he will answer like this.

B=Truth: Yes or No

B=Liar: Yes or No

So If i get an answer I can safely assume B is either a liar or a truth teller, if I do not get an answer then C is either a liar or a truth teller.

based on that I will ask either B or C (the one I know not to be the random answerer).

"Would you tell me the Left path leads to Heaven if I asked you?" If he answers Yes - it is the path, if he answers No, the right path is the correct path.

A very good suggestion. Not the answer I was looking for, but I definately have to award you a point for this one. This is a solution to the problem as stated in the OP.

To narrow down the possibilities let me add to the OP that these figures know all about past, present, and future events. And therefore they also know what the random-replyer will answer.

[Guest]

A very good suggestion. Not the answer I was looking for, but I definately have to award you a point for this one. This is a solution to the problem as stated in the OP.

To narrow down the possibilities let me add to the OP that these figures know all about past, present, and future events. And therefore they also know what the random-replyer will answer.

If it's known beforehand, then it's not really a random response, is it

[Guest]

If it's known beforehand, then it's not really a random response, is it

This would be the sort of paradox you would be faced with regularly if you believe in Karma, I suppose. Still people believe in it.

Yet, I do agree that I'm stretching it a bit here

[plasmid]

To the person on the left: "If I were to ask you whether or not the person in the middle is the random answerer, what would your response be?"

If the answer was "no", ask the person in the middle: "If I were to ask you whether the road to my right is the way to heaven, what would your response be?"

If the first answer was "yes", ask the second question to the person on the other end instead.

If the response to the second question was "yes", then take the road to your right. If it was "no", then take the road to your left.

Open the second spoiler if you need to see my logic.

First off, for anyone who hasn't seen this trick before, the reason why I'm asking "If I were to ask you ___, what would your response be?" is because you can ask such a question to either the truth teller or the liar and get a "truthful" response. That's because the liar would lie if you just asked the question outright, but since you're asking how he would respond if you asked the question, he has to lie about what his lying response would be; sort of giving a double negative to a yes/no question to yield the truth.

The whole point of the first question is to make sure that you're NOT asking the second question to the random answerer. If the person you asked the first question to was either the truth teller or the liar, then they will reveal whether or not the person in the middle is the random answerer. If the middle guy IS NOT the random answerer, ask him the second question. If the middle guy IS the random answerer, ask the second question to the guy at the other end.

But what if the guy you asked the first question to was the random answerer? Well then, it doesn't matter what he answered, you're still going to ask the second question to the liar or the truth teller either way.

[Guest]

First off, for anyone who hasn't seen this trick before, the reason why I'm asking "If I were to ask you ___, what would your response be?" is because you can ask such a question to either the truth teller or the liar and get a "truthful" response. That's because the liar would lie if you just asked the question outright, but since you're asking how he would respond if you asked the question, he has to lie about what his lying response would be; sort of giving a double negative to a yes/no question to yield the truth.

The whole point of the first question is to make sure that you're NOT asking the second question to the random answerer. If the person you asked the first question to was either the truth teller or the liar, then they will reveal whether or not the person in the middle is the random answerer. If the middle guy IS NOT the random answerer, ask him the second question. If the middle guy IS the random answerer, ask the second question to the guy at the other end.

But what if the guy you asked the first question to was the random answerer? Well then, it doesn't matter what he answered, you're still going to ask the second question to the liar or the truth teller either way.

To the person on the left: "If I were to ask you whether or not the person in the middle is the random answerer, what would your response be?"

If the answer was "no", ask the person in the middle: "If I were to ask you whether the road to my right is the way to heaven, what would your response be?"

If the first answer was "yes", ask the second question to the person on the other end instead.

If the response to the second question was "yes", then take the road to your right. If it was "no", then take the road to your left.

Open the second spoiler if you need to see my logic.

This is definately a solution to the new wording of the puzzle. Well done, Plasmid

[Guest]

First off, for anyone who hasn't seen this trick before, the reason why I'm asking "If I were to ask you ___, what would your response be?" is because you can ask such a question to either the truth teller or the liar and get a "truthful" response. That's because the liar would lie if you just asked the question outright, but since you're asking how he would respond if you asked the question, he has to lie about what his lying response would be; sort of giving a double negative to a yes/no question to yield the truth.

The whole point of the first question is to make sure that you're NOT asking the second question to the random answerer. If the person you asked the first question to was either the truth teller or the liar, then they will reveal whether or not the person in the middle is the random answerer. If the middle guy IS NOT the random answerer, ask him the second question. If the middle guy IS the random answerer, ask the second question to the guy at the other end.

But what if the guy you asked the first question to was the random answerer? Well then, it doesn't matter what he answered, you're still going to ask the second question to the liar or the truth teller either way.

To the person on the left: "If I were to ask you whether or not the person in the middle is the random answerer, what would your response be?"

If the answer was "no", ask the person in the middle: "If I were to ask you whether the road to my right is the way to heaven, what would your response be?"

If the first answer was "yes", ask the second question to the person on the other end instead.

If the response to the second question was "yes", then take the road to your right. If it was "no", then take the road to your left.

Open the second spoiler if you need to see my logic.

answer is "no"

could be the truth teller saying "no", therefore the middle person is NOT the random answerer

could be the liar saying "no", meaning he would really say "yes" if you asked the answer outright - so the middle person is NOT the random answerer

BUT, if the person you ask that of is the random answerer and the answer is "no", there is no logic by which to conclude anything.

"no" could mean he is lying and would have said "yes" (which would be a lie)

"no" could mean he is telling the truth and would have said "no"(which would be a truth)

answer is "yes"

could be the truth teller saying "yes", therefore the middle person IS the random answerer

could be the truth teller saying "yes", meaning he would really say "no" if you asked the question outright

BUT, if the person you ask that of is the random answerer and the answer is "yes":

"yes" could mean he is lying and would have said "no" (the truth)

"yes" could mean he is telling the truth and would have said "yes" (a lie)

as you stated in your logic... the random answerer cannot be counted upon for a definitive true or false answer. and so if you happen to ask the random answerer first (your logic assumes you will only ever ask either the liar or the truth teller first), you are likely presented with a lie of some form or antother (as presented above) but cannot logically deduce which form the answer takes: a lie about the truth, a truth about the truth, or a truth about the lie.

--------

nevermind....

I forgot something. *bangs head on wall*

if the first person you ask happens to be the random answerer, you'd be switching people anyhow - so it doesn't matter what his answer is.

Edited April 3, 2009 by spikejones

[preflop]

answer is "no"

could be the truth teller saying "no", therefore the middle person is NOT the random answerer

could be the liar saying "no", meaning he would really say "yes" if you asked the answer outright - so the middle person is NOT the random answerer

BUT, if the person you ask that of is the random answerer and the answer is "no", there is no logic by which to conclude anything.

"no" could mean he is lying and would have said "yes" (which would be a lie)

"no" could mean he is telling the truth and would have said "no"(which would be a truth)

answer is "yes"

could be the truth teller saying "yes", therefore the middle person IS the random answerer

could be the truth teller saying "yes", meaning he would really say "no" if you asked the question outright

BUT, if the person you ask that of is the random answerer and the answer is "yes":

"yes" could mean he is lying and would have said "no" (the truth)

"yes" could mean he is telling the truth and would have said "yes" (a lie)

as you stated in your logic... the random answerer cannot be counted upon for a definitive true or false answer. and so if you happen to ask the random answerer first (your logic assumes you will only ever ask either the liar or the truth teller first), you are likely presented with a lie of some form or antother (as presented above) but cannot logically deduce which form the answer takes: a lie about the truth, a truth about the truth, or a truth about the lie.

plasmid's logic works

you are just trying to eliminate the the random answerer in with the first question.

It doesn't matter if you ask the random person first, since the second question is always posed to one of the other two. So if the random person tells you a lie, or the truth it does not matter because the second person will always be either the truth teller or the liar.

Also his first question is worded in the double negative way, so that both liars and truth tellers effectively answer the question truthfully.

[Guest]

If you could ask one a question you could narrow it down.

So If you asked someone, "Do I have red hair", and you did," Yes or no?"

And they answered yes then you know they could either be the truth person or the random person.

Tha's as much I could Figure out

Was I on the right track?

[Guest]

If you could ask one a question you could narrow it down.

So If you asked someone, "Do I have red hair", and you did," Yes or no?"

And they answered yes then you know they could either be the truth person or the random person.

Tha's as much I could Figure out

Was I on the right track?

Of course, I can't tell you that your approach is wrong since I do not know all possibilities. I must say that I doubt that you will solve the puzzle that way for the simple reason that your final question could still be asked to the random person, and therefore the outcome would be random.

[Guest]

plasmid's logic works

you are just trying to eliminate the the random answerer in with the first question.

It doesn't matter if you ask the random person first, since the second question is always posed to one of the other two. So if the random person tells you a lie, or the truth it does not matter because the second person will always be either the truth teller or the liar.

Also his first question is worded in the double negative way, so that both liars and truth tellers effectively answer the question truthfully.

yeah... I edited that to note that I just realized in effect what you are saying