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Can't solve this riddle

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He doesn't answer completely randomly, he randomly decides whether or not his answer will be the truth. If the double negative traps the liar into giving you the right direction, and at the same time doesn't affect the truth-teller's answer, then the random answerer ends up giving you the correct response regardless of which way he "decides" to answer you.

I do like the added italic emphasis, but it amounts to the exact same thing.

You guys have made it a condition that he decides to tell the truth or lie about the question rather than give a random answer, which is completely different.
 
The random guy never lies or tells the truth--he doesn't know anything and just picks a random response. His response has no meaning and provides no insight whatsoever. The goal of the puzzle is to identify that he is random, and thus to be ignored completely.
Since the liar and truth teller always have the same response to that particular question, you can just ask all three and go whichever way gets 2 or 3 of the same response.
 
I do like the added italic emphasis, but it amounts to the exact same thing.

You guys have made it a condition that he decides to tell the truth or lie about the question rather than give a random answer, which is completely different.

No it doesn't amount to the same thing. In your case he doesn't know anything and just says yes or no at random. In the case the OP is discussing he "sometimes lies and sometimes tells the truth". That's what we're discussing. They are indeed different questions.

I wasn't familiar with the second case outside of what's being talked about here. If he's supposed to be truly "random" and not respond to any questions logically, then yeah, it doesn't work.

EDIT: It looks like the OP was edited? Maybe that's where we're getting confused.
 
a dishonest man you can always trust to be dishonest. it's the honest ones you want to watch out for, because you can never predict when they're going to do something incredibly stupid
 
Okay, which one of you is lying about how this riddle goes....
There are really two different scenarios:
1. Third man picks a completely random answer no matter what, in which case you either need to be able to ask each man the same question or the riddle is impossible.
2. The third man randomly lies or tells the truth, in which case you just need to ask him one question that will yield the same answer regardless of whether he lies or tells the truth.

If the random man has a truly random answer, logic won't work on him and it'll be impossible to get anything useful out of him or even identify him unless he changes his answer to the same question. It's like trying to play chess against someone who keeps flipping over the board. If you can still ask the other two, you can use a question that will get the same response if they are lying or not, and thus will always get at least 2 of the same answer.
 
Since the liar and truth teller always have the same response to that particular question, you can just ask all three and go whichever way gets 2 or 3 of the same response.

The liar and the truth teller dont have the same


Say left is the correct way
To the liar- "which way do I go?" - "right"
to the truthful man- "Which way do I go?" - "left"



But yes, assuming this 3rd man is luck, you all have a 50%-50% shot of being wrong.
As for me (and anyone who knows me and my borderline ridiculous rng/luck, to the point of winning 1/1000 things and not being surprised) I'll just ask all 3 and presume I lucked out with him telling the truth. Or maybe ask none. It's the same, I win when I pick...probably. *gulps*
:P

Yeah, we're all screwed in reality.
 
The liar and the truth teller dont have the same


Say left is the correct way
To the liar- "which way do I go?" - "right"
to the truthful man- "Which way do I go?" - "left"



But yes, assuming this 3rd man is luck, you all have a 50%-50% shot of being wrong.
As for me (and anyone who knows me and my borderline ridiculous rng/luck, to the point of winning 1/1000 things and not being surprised) I'll just ask all 3 and presume I lucked out with him telling the truth. Or maybe ask none. It's the same, I win when I pick...probably. *gulps*
:P

Yeah, we're all screwed in reality.
The question I'm referring to is
"Would you answer yes if the left path leads to my destination?"
 
The liar and the truth teller dont have the same


Say left is the correct way
To the liar- "which way do I go?" - "right"
to the truthful man- "Which way do I go?" - "left"



But yes, assuming this 3rd man is luck, you all have a 50%-50% shot of being wrong.
As for me (and anyone who knows me and my borderline ridiculous rng/luck, to the point of winning 1/1000 things and not being surprised) I'll just ask all 3 and presume I lucked out with him telling the truth. Or maybe ask none. It's the same, I win when I pick...probably. *gulps*
:P

Yeah, we're all screwed in reality.


The thing is "Which way do I go?" is a slightly different question from "Would you answer 'yes' if I asked you if left was the correct path?".

See Erheller's response.
 
Yeah. The guy I was replying to was solving the first one, not the second. But I just read that and yes, that is the correct way to go about it.
What? I was talking about the second one. The numbers represent the scenarios for how the third man behaves in the second question.
 
I have two riddles. One I have figured out, the other I can't figure out. I'll give them both. If you can figure it out, answer in a spoiler. No cheating!

Solved Riddle:
You walk down a road until you hit a fork. One direction will lead you to your destination, the other will leave you lost. There are two men at the fork in the road. One always lies, the other always tells the truth. You can only ask one question and only one is allowed to answer. What do you ask and who do you ask it to in order to determine the correct way to go. Both know the correct way.

Y'know, it helps a great deal if you also specify that you don't know which guy is which!
 
Answer to the second one, I think:

Would you say 'yes' if I asked you if the left path leads to my destination? (If the answer is yes, go down the left path; if no, go down the right)


There's a potential issue with this, depending on the exact specification of Random Guy. The question needs to make it clear if his randomness is set per entire question or per individual query, because the statement here is dependent on it being the same setting for both the "Does the left path lead to my destination" and "Would you say yes". If the honesty differs between those two queries - if he lies for one query, tells the truth for the other - you have a problem.

(Also, it's petty, but "Would you say yes" is subvertible if you'd say "Sure!" instead!)
 
There's a potential issue with this, depending on the exact specification of Random Guy. The question needs to make it clear if his randomness is set per entire question or per individual query, because the statement here is dependent on it being the same setting for both the "Does the left path lead to my destination" and "Would you say yes". If the honesty differs between those two queries - if he lies for one query, tells the truth for the other - you have a problem.

(Also, it's petty, but "Would you say yes" is subvertible if you'd say "Sure!" instead!)

You still get three questions. So just ask them all the "Would you answer 'Yes'..", and if one answers differently from the other two, he's the random one. Whose answer you can ignore.

Now if you had only one question, then you'd potentially be in trouble. But you'd still have a better chance than pure random 50/50.
 
You still get three questions. So just ask them all the "Would you answer 'Yes'..", and if one answers differently from the other two, he's the random one. Whose answer you can ignore.

Now if you had only one question, then you'd potentially be in trouble. But you'd still have a better chance than pure random 50/50.

Yeah, the three questions is new to me, and I don't think it's in the traditional version of the puzzle. I think the traditional one relies on what I indicated about Random Guy answering consistently within the confines of the full query.
 
I have two riddles. One I have figured out, the other I can't figure out. I'll give them both. If you can figure it out, answer in a spoiler. No cheating!

Unsolved Riddle:
It's the same riddle, but add a third person who sometimes lies and sometimes tells the truth. You can ask three questions. There is some dispute on how many questions you may ask here.

There's no answer to this one, if you're using the same paths scenario as the first riddle.

EDIT: This however, does have a solution.

You are the most eligible bachelor in the kingdom, and as such the King has invited you to his castle so that you may choose one of his three daughters to marry. The eldest princess is honest and always tells the truth. The youngest princess is dishonest and always lies. The middle princess is mischievous and tells the truth sometimes and lies the rest of the time.

As you will be forever married to one of the princesses, you want to marry the eldest (truth-teller) or the youngest (liar) because at least you know where you stand with them.

The problem is that you cannot tell which sister is which just by their appearance, and the King will only grant you ONE yes or no question which you may only address to ONE of the sisters. What yes or no question can you ask which will ensure you do not marry the middle sister?
 
XOwqsMJ.jpg


Yup
 
The first riddle relies upon the supposition that the two men know each other's truthfulness. It's of course easy to solve if this is the case.
 
So the first riddle you don't know which guy is which right? The "who do you ask" implies that you know. Because it's way too easy then, just ask the truth teller.
 
bumping this as it's the newest riddle thread I could find, and I just won a tablet and a job interview for answering the following riddle which I present to you GAF:


A room contains 300 boxes labeled '1' to '300', and 300 balls (similarly labeled) are randomly placed inside them, one per box. Person 1 is allowed to enter the room and open all boxes to see their contents. They are also allowed to switch the positions of any 2 balls, and they can make no more than two such switches. Person 1 is then removed from the scene.

After that, the boxes are closed and Person 2 enters the room and is given a random number between 1 and 300. They must find the corresponding ball while opening no more than 100 boxes.

Person 1 and 2 are only allowed to communicate once, before either of them enters the room. What strategy can they decide on that guarantees the correct ball is found?


Please spoiler your answers, as always. Also, you must provide a full explanation for your answer.
 
Second one seems easy? Unless I missed something.

Three questions:
Ask the first guy which way the second guy would point me.
Ask the second guy which way the third guy would point me.
Ask the third guy which way the first would point me.

For the sake of making it simple, let's pretend 1 tells the truth, second lies, third is random.

First answer points to loss.
Second can't answer because he has no way to know the lie/truth
Third is now irrelevent because you know he is the one who is random. The right way is the opposite of the first answer.

Edit: Actually only two questions are required now that I think about it.

Not sure if this was already answered, didn't check the rest of the thread.
 
Second one seems easy? Unless I missed something.

Edit: Actually only two questions are required now that I think about it.

Not sure if this was already answered, didn't check the rest of the thread.

what happens if the first one you ask is the "random" one? you'd still need to ask the other two.

also, as discussed in this thread, he may not be random. He may decide to lie or tell the truth according to some scheme that is known to the others, so that they could answer for him.
 
what happens if the first one you ask is the "random" one? you'd still need to ask the other two.

also, as discussed in this thread, he may not be random. He may decide to lie or tell the truth according to some scheme that is known to the others, so that they could answer for him.

No, you ask the first one, get random answer, ask second one, get an answer still, it wasn't an "I don't know?" First one was the random guy.
 
bumping this as it's the newest riddle thread I could find, and I just won a tablet and a job interview for answering the following riddle which I present to you GAF:


A room contains 300 boxes labeled '1' to '300', and 300 balls (similarly labeled) are randomly placed inside them, one per box. Person 1 is allowed to enter the room and open all boxes to see their contents. They are also allowed to switch the positions of any 2 balls, and they can make no more than two such switches.

After that, Person 2 enters the room and is given a random number between 1 and 300. They must find the corresponding ball while opening no more than 100 boxes.

Person 1 and 2 are only allowed to communicate once, before either of them enters the room. What strategy can they decide on that guarantees the correct ball is found?


Please spoiler your answers, as always. Also, you must provide a full explanation for your answer.

I'm guessing person 1 isn't allowed to move the boxes, correct?
 
bumping this as it's the newest riddle thread I could find, and I just won a tablet and a job interview for answering the following riddle which I present to you GAF:


A room contains 300 boxes labeled '1' to '300', and 300 balls (similarly labeled) are randomly placed inside them, one per box. Person 1 is allowed to enter the room and open all boxes to see their contents. They are also allowed to switch the positions of any 2 balls, and they can make no more than two such switches.

After that, Person 2 enters the room and is given a random number between 1 and 300. They must find the corresponding ball while opening no more than 100 boxes.

Person 1 and 2 are only allowed to communicate once, before either of them enters the room. What strategy can they decide on that guarantees the correct ball is found?


Please spoiler your answers, as always. Also, you must provide a full explanation for your answer.

Just to clarify: The start state isn't that Ball 1 starts in Box 1, Ball 2 starts in Box 2, etc, right? "Similarly labelled" is a little ambiguous.

(Also, it's pettiness, but you probably ought to elaborate that after person 1's done their job, the boxes are closed again! Otherwise it's "Person 1 opens all the boxes. Person 2 doesn't open any boxes, but looks in all the open boxes :-)


Edit: Wait, missed the 'randomly'. That clarifies the 'similarly labelled', in the way I expected.
 
I'm guessing person 1 isn't allowed to move the boxes, correct?

Correct. Person one is only allowed to look inside all boxes, and switch between 2 balls, at most twice.

Just to clarify: The start state isn't that Ball 1 starts in Box 1, Ball 2 starts in Box 2, etc, right? "Similarly labelled" is a little ambiguous.

(Also, it's pettiness, but you probably ought to elaborate that after person 1's done their job, the boxes are closed again! Otherwise it's "Person 1 opens all the boxes. Person 2 doesn't open any boxes, but looks in all the open boxes :-)

The start state is random: the 300 balls are randomly placed in the 300 boxes, one ball per box.
Regarding the pettiness, I realized that, figured it would be self explanatory ;)
(edited it anyway)
 
that only addresses my first concern though. there's a solution that addresses the second too.

It means the second answer you got is valid.
Ask random guy what guy 2 would say, get random answer.
Ask guy 2 what guy 3 would say, get answer.
Don't bother asking guy 3, he's going to say "I don't know" because now you know first guy is random.
 
The start state is random. Regarding the pettiness, I realized that, figured it would be self explanatory ;)

Heh. Yes, that's fair enough. But there are puzzles like this where the petty answer is the key, so I have to check!

I haven't solved it, but my train of thought so far:

The only thing I've latched onto thus far is that I'd have to assume that the two switches are something to do with splitting into three blocks of 100 boxes. The only communication Player 2 gets in the room is anything Player 1 can convey with the information they charge the boxes with. However, Player 1 doesn't know the target value.

Player 2 is going to open a box. That'll either be an (arbitrary?) previously-agreed one or the target number's one, those are the only two logical choices. It'll either contain a random number (if it's the target number box) or something Player 1 can dictate (if it's a previously-agreed one). Or, should the random number happen to *be* the same as the agreed box one, by coincidence, it'll contain Player 1's info despite everything.

My first question:

Is the only information Player 1 is imparting when Player 2 is in the room conveyed via the numbers in the boxes?
 
Heh. Yes, that's fair enough. But there are puzzles like this where the petty answer is the key, so I have to check!

I'd never ask those kinds of "puzzles", and more importantly, neither would a job interview :P


It means the second answer you got is valid.
Ask random guy what guy 2 would say, get random answer.
Ask guy 2 what guy 3 would say, get answer.
Don't bother asking guy 3, he's going to say "I don't know" because now you know first guy is random.

I understood what you were saying the first time. But I also raised a second concern, that was about the solution in general rather than the number of questions it would require. If the third person isn't random but rather chooses to lie or tell the truth according to a scheme known by the other two, then they would never have to answer "I don't know". There's a different solution to this riddle that doesn't have this problem.
 
I'd never ask those kinds of "puzzles", and more importantly, neither would a job interview :P

In a university entrance interview, for computer graphics, I was asked how I'd develop an algorithm to draw a circle.

I asked if there was any limitation to hardware or programming language?

I was told no.

I said "Okay, I'll use the CIRCLE command from Spectrum BASIC".

(I did then go on to answer it properly, but I think the interviewer was amused. I got in!)
 
In a university entrance interview, for computer graphics, I was asked how I'd develop an algorithm to draw a circle.

I asked if there was any limitation to hardware or programming language?

I was told no.

I said "Okay, I'll use the CIRCLE command from Spectrum BASIC".

(I did then go on to answer it properly, but I think the interviewer was amused. I got in!)

LOL.

(out of curiousity: Is there anything better than Bresenham's method?)


I haven't solved it, but my train of thought so far:


My first question:

Is the only information Player 1 is imparting when Player 2 is in the room conveyed via the numbers in the boxes?

Player 1 essentially leaves the room before Player 2 enters. I'll add that to the original post for clarity. So the only information they can share is given by the initial strategy which is then enacted by Player 1.
 
Person 1 and 2 are only allowed to communicate once, before either of them enters the room. What strategy can they decide on that guarantees the correct ball is found?

Is this phrasing correct? If so, then the solution to the problem is for person 2 relay the task to person 1 since person 1 knows the location of all balls.
 
Player 1 essentially leaves the room before Player 2 enters. I'll add that to the original post for clarity. So the only information they can share is given by the initial strategy which is then enacted by Player 1.

Yes, but my point was
that that initial strategy must implicitly involve some information being passed on to Player 2 in how it was utilised. So the first task is figuring out what information can be conveyed with the resources at Player 1's disposal, and then trying to figure out how that information can be used to indicate to Player 2 how to go about opening their remaining boxes.

Hence my question, which boils down to: Is the only data point Player 1 is offering buried in the balls, or is there some other more subtle means of data conveyance to work out?
 
Is this phrasing correct? If so, then the solution to the problem is for person 2 relay the task to person 1 since person 1 knows the location of all balls.

Player 1 doesn't know the location of all the balls at the point the communication is allowed to take place; neither player knows the target ball value at the point the communication is allowed to take place.
 
Is this phrasing correct? If so, then the solution to the problem is for person 2 relay the task to person 1 since person 1 knows the location of all balls.

Person 1 enters, does whatever was agreed upon, then leaves. Person 2 then enters and gets a random number to find. This isn't a trick question.

The heck?
That deserves an explanation.
I know man, I thought it was weird too. Hence I made an effort to answer the riddle. Don't know anything beyond that as the interview/tablet gifting hasn't taken place yet.

Yes, but my point was
that that initial strategy must implicitly involve some information being passed on to Player 2 in how it was utilised. So the first task is figuring out what information can be conveyed with the resources at Player 1's disposal, and then trying to figure out how that information can be used to indicate to Player 2 how to go about opening their remaining boxes.

Hence my question, which boils down to: Is the only data point Player 1 is offering buried in the balls, or is there some other more subtle means of data conveyance to work out?
There is no subtle means of conveying additional data.
 
A question:

If we were to reduce the parameters to 9 boxes, 9 balls, 2 exchanges, player 2 allowed to open three boxes, would it still be solvable by the exact same method?

Curious if the scale is confusing me or if it's actually necessary to the puzzle.

Oh, one other question, and I won't spoiler this one, because I'm double-checking some of the phrasing:

Are we after a strategy that guarantees success or one that maximises the chance of success?
 
For the second one

You ask one of them how many people are standing next to him and sees if he lies. If he does lie, repeat the question to the next guy. If he lies too, you know the third guy tells the truth so you ask him which way to go.

Not sure if this is legit or not lol
 
Anyone who listens to XFM or the ricky gervais podcasts knows the answer to the first one. Ricky covered it and explained the answer.

I wont post it as if no one has heard it yet ill let them come up with it.

"I've got some post for God here... uhhhh...."

I remeber that episode!
 
I have two riddles. One I have figured out, the other I can't figure out. I'll give them both. If you can figure it out, answer in a spoiler. No cheating!

Solved Riddle:
You walk down a road until you hit a fork. One direction will lead you to your destination, the other will leave you lost. There are two men at the fork in the road. One always lies, the other always tells the truth. You can only ask one question and only one is allowed to answer. What do you ask and who do you ask it to in order to determine the correct way to go. Both know the correct way.


Unsolved Riddle:
It's the same riddle, but add a third person who sometimes lies and sometimes tells the truth. You can ask three questions. There is some dispute on how many questions you may ask here.

Ask which way the liar would say to go

For the second one I think you must have got the riddle or number of questions wrong in some way OP, becase the answer is simple

Ask each of them which way the liar would say to go. At least 2/3 would give the correct answer.
 
A question:

If we were to reduce the parameters to 9 boxes, 9 balls, 2 exchanges, player 2 allowed to open three boxes, would it still be solvable by the exact same method?

Curious if the scale is confusing me or if it's actually necessary to the puzzle.

are you sure you want a hint?
 
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