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Can't solve this riddle

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DivineRage002 said:
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.
Click to expand...


But if you're unlucky you have to ask five times:
First person is random guy = A
Second person is liar = B
Third person is truth = C

(1)ask A about B
(2)ask A about C
(3)ask B about A
(4)ask B about C

Now you know C has to be the truth guy as no one said "I don't know".

(5)ask C about A to know if either A or B is the liar.

Take the opposite of the answer that the liar (B) gave when asked about C.


edit: I misread. You assume the liar also can't give an answer? I don't think so, by not saying "I don't know" he's lying and fulfills his role

I don't know how that's supposed to work with 3 questions, maybe by asking different ones?
 
Actually, let's get a bit metapuzzley:

You noted that you solved the puzzle and that won you a tablet and a job interview. That suggests that the context for the contest was that it suggests some sort of marketable skill. It was probably a showcase from some employer looking for likely candidates. There's only a few types of employers that I can think of that do that sort of thing, and that suggests - to me - that we're looking at an employer who works heavily with some complicated algorithmic challenge like, say, encryption.

I'm not quite sure how to use that chain of thought, but it's sort of leading me towards a style of solution.
 
efyu_lemonardo said:
guarantees it
Click to expand...

I can think of only one way to do that.

As mclem said, you'll have to be able to split your boxes in 3 groups with your strategy.
1-100
101-200
201-300
I can't think of any other way to guarantee the result without this. Is there any?

Problem is I don't see how you can achieve this while only being allowed to switch balls.
 
Since the balls are random how can you swap 2?

Unless it's just I want this ball in this box and the other ball and box remain a mystery during the swap
 
kingwingin said:
Since the balls are random how can you swap 2?

Unless it's just I want this ball in this box and the other ball and box remain a mystery during the swap
Click to expand...

reread the riddle. The person performing the 2 swaps is allowed to open all the boxes beforehand. So for them the positions aren't random.
 
I can do it really easily if player 1's allowed to do a hundred switches!

Clearly he just needs to bribe the supervisor to look the other way.

efyu_lemonardo said:
reread the riddle. The person performing the 2 swaps is allowed to open all the boxes beforehand. So for them the positions aren't random.
Click to expand...

There are, however, still 296 balls that Player 1 has no ultimate control over. That's my big sticking point at the moment.

Edit: In fact, 298 balls Player 1 has no control over if their core objective is to get a certain ball into a certain box, which I still feel is key for the start of P2's strategy. The effect on the ball currently in that box is out of Player 1's control.
 
mclem said:
I can do it really easily if player 1's allowed to do a hundred switches!

Clearly he just needs to bribe the supervisor to look the other way.



There are, however, still 296 balls that Player 1 has no ultimate control over. That's my big sticking point at the moment.

Edit: In fact, 298 balls Player 1 has no control over if their core objective is to get a certain ball into a certain box, which I still feel is key for the start of P2's strategy. The effect on the ball currently in that box is out of Player 1's control.
Click to expand...

it's true that player 1 has no control over most of the balls. But since player 2 has 100 guesses, player 1 may not need to have control over most balls.
 
Person 1 has to somehow count the balls and leave a hint they decided on for person 2. Person 2's # can't matter since it's random.

Since the balls are random what if they happen to all be in proper boxes? Half are right boxes? All wrong boxes?

I should be in bed lol.

person 1 lines up the boxes in order of ball #
 
efyu_lemonardo said:
it's true that player 1 has no control over most of the balls. But since player 2 has 100 guesses, player 1 may not need to have control over most balls.
Click to expand...

Is person 1 allowed to move the ball inside the box? Like for example put the ball with the number on top, and on the next box move the ball so the number is on the bottom, etc?
 
I'll be away for the next few hours, so here's a major guideline, for those interested:

if you were player 2, how would you choose which 100 boxes to open, based on the number you were given?


OPTIONAL: EVEN BIGGER HINT FOR THE GUIDELINE

Is there a strategy for choosing which 100 boxes to open that, while not perfect, only needs minor fixing to work?
 
got to go! these will be my last replies for a couple hours

Caronte said:
I don't like this game.
Click to expand...

kingwingin said:
I don't think the game likes us
Click to expand...

Don't feel bad if this one's tough to crack for you. While it's possible to solve based on logic and strong intuition, having some university level knowledge of math is very helpful.

Striek said:
I doubt there is a solution following the guidelines listed.
Click to expand...

I'll reveal it if enough time passes and it hasn't been solved.
 
I think I got it?

Ask two of them "What would your brothers tell me if I asked them whether they are liars or truth tellers?"

A - Truther - Response (B would tell you that he tells the truth, and C will either tell you he is a liar or a truther.)

B - Liar - Response (A would tell you he is a liar, and C would tell you that he tells the truth), or (A would tell you he is a liar, and C tell you the the liar)

C - Random - Response (A would tell you that he tells the truth, B would tell you he tells the truth), or (A would tell you he is a liar, and B would tell you he is a liar)

A's response is always the same, so if you get his answer. You ask him which way to go. If you ask the other two and don't get his answer, you know that he is the one you didn't ask.

B will never say that C is both a liar and a truther.
He will say that they would say they are either liars, or telling the truth.

Possible answers

A (B would tell you that he tells the truth, and C will either tell you he is a liar or a truther.)
B (A would tell you he is a liar, and C tell you the the truth)
If any of the answers include A's answer. You just ask A.

A (B would tell you that he tells the truth, and C will either tell you he is a liar or a truther.)
B (A would tell you he is a liar, and C tell you the the liar)
Ask A.

A (B would tell you that he tells the truth, and C will either tell you he is a liar or a truther.)
C (A would tell you that he tells the truth, B would tell you he tells the truth)
Ask A.

A (B would tell you that he tells the truth, and C will either tell you he is a liar or a truther.)
C (A would tell you he is a liar, and B would tell you he is a liar)
Ask A.

B (A would tell you he is a liar, and C would tell you that he tells the truth)
C (A would tell you that he tells the truth, B would tell you he tells the truth)
A's answer is not included, so you know that B, and C are not truthers. You ask A.


B (A would tell you he is a liar, and C would tell you that he tells the truth)
C (A would tell you he is a liar, and B would tell you he is a liar)
A's answer is not included, so you know that B, and C are not truthers. You ask A.

B (A would tell you he is a liar, and C tell you the the liar)
C(A would tell you that he tells the truth, B would tell you he tells the truth)
A's answer is not included, so you know that B, and C are not truthers. You ask A.

B (A would tell you he is a liar, and C would tell you he is a liar)
C (A would tell you he is a liar, and B would tell you he is a liar)
A's answer is not included, so you know that B, and C are not truthers. You ask A.

Edit: Oh there's a new one.
 
efyu_lemonardo said:
I'll be away for the next few hours, so here's a major guideline, for those interested:

if you were player 2, how would you choose which 100 boxes to open, based on the number you were given?


OPTIONAL: EVEN BIGGER HINT FOR THE GUIDELINE

Is there a strategy for choosing which 100 boxes to open that, while not perfect, only needs minor fixing to work?
Click to expand...

I mean if its all random, player 1 having any knowledge about the balls is pointless. And him moving one doesnt help player 2 since player 2 will have no idea what was/wasnt moved.
 
I feel like there is missing information in the question.


Also as person 2, if all the balls are random how could I possibly even decide which boxes to open? And how can person 1 move balls when they are random? Swap ball 8 and 120 but which box did they go into?
 
kingwingin said:
I feel like there is missing information in the question.

I can swap ball 10 and 30 but what box did they go into? I can put ball 9 in box 9 but what was in the box before that?
Click to expand...
Presumably you can devise a system to use the two balls to split the balls into three useful categories (for the hundred guesses) but I don't see how. I mean can do some complicated stuff that can communicate some information like put in box 100 the mean of the first 99 balls or put ball 217 in the nearest 25th box to ball 83....
 
pompidu said:
I mean if its all random, player 1 having any knowledge about the balls is pointless. And him moving one doesnt help player 2 since player 2 will have no idea what was/wasnt moved.
Click to expand...

kingwingin said:
Also as person 2, if all the balls are random how could I possibly even decide which boxes to open?
Click to expand...

I assume the intent is "Okay, I will swap ball X into box 1. Open box 1. Ball X will tell you something." I just can't figure out what a useful 'something' is.

And how can person 1 move balls when they are random? Swap ball 8 and 120 but which box did they go into?
Click to expand...

If ball 8 is in box 150 and ball 120 is in box 201, after swapping ball 8 will be in box 201 and ball 120 will be in box 150.


kingwingin said:
I feel like there is missing information in the question.
Click to expand...

I'm wondering that, but it's an easy fallacy to assume there's a problem with the puzzle when instead you simply haven't figured it out yet! I wrote something about that a while ago.

efyu_lemonardo said:
I'll be away for the next few hours, so here's a major guideline, for those interested:

if you were player 2, how would you choose which 100 boxes to open, based on the number you were given?
Click to expand...

As best as I can determine:

The only relationship between the number and the boxes is any information Player 1 manages to impart. The number Player 2 was given is mostly irrelevant; Player 1 does not know it, so Player 1 cannot use it in order to determine what information they need to impart; Player 1 instead needs to impart sufficient information about the entire system.

...and then I come to a standstill.
 
Meikyuu.jpg


IT'S TIME TO D-D-D-D-D-DUEL
 
Solved - At best it takes 3 questions if you are lucky. Use brute force to determine the occasional lair. Keep asking all of them which way one of them will say is the right direction. The person who changes their answer will be the occasional liar. Then apply the same logic used in the first riddle When you have figured out who occasionally lies.
 
Striek said:
Presumably you can devise a system to use the two balls to split the balls into three useful categories (for the hundred guesses) but I don't see how. I mean can do some complicated stuff that can communicate some information like put in box 100 the mean of the first 99 balls or put ball 217 in the nearest 25th box to ball
Click to expand...

That seems to complicated to calculate means out since it was mentioned we could use logic and intuition to solve.

And a mean wouldn't tell someone what balls exactly were in each category right? I'm assuming you could get the same mean even with different ball values
 
mclem said:
The only relationship between the number and the boxes is any information Player 1 manages to impart. The number Player 2 was given is mostly irrelevant; Player 1 does not know it, so Player 1 cannot use it in order to determine what information they need to impart; Player 1 instead needs to impart sufficient information about the entire system.

...and then I come to a standstill.
Click to expand...

Same...

Player 1 can only give 2 numbers to Player 2 (box 1 and 2) and those numbers have to define 3 differents groups of 100 boxes.

I'll just wait for the answer because I can't solve that.
 
kingwingin said:
That seems to complicated to calculate means out since it was mentioned we could use logic and intuition to solve.

And a mean wouldn't tell someone what balls exactly were in each category right? I'm assuming you could get the same mean even with different ball values
Click to expand...
Well yeah those were just examples of information you could convey, not that it would be useful or practical. Just trying to stir creative juices.

That was just a way that player one can communicate something about the system as a whole, which would obviously be part of any solution.
 
Striek said:
Presumably you can devise a system to use the two balls to split the balls into three useful categories (for the hundred guesses)
Click to expand...

Actually, that leads to an interesting question: Does Player 2 decide which hundred to open straight away (or at least, after determining which information Player 1 is imparting), or do they gain more information from their 'wrong' boxes to lead them to the right answer?

One thing I'm wondering - although this does fall into the fallacious trap I mentioned earlier of assuming there's a fault with the question -
is whether the balls are randomly laid out such that there's guaranteed to be a single loop; each ball points to a box which points to another ball and so on, and until you get back to the start, having opened all boxes.

That I can see forming the basis of the puzzle - two swaps could be used to effectively split one closed loop into three distinct 100-box closed loops. But it's certainly not specified in the question!

Edit: Actually, if it *is* that, that's a full solution!
Player 2 opens the box corresponding to their number first, then opens the box that that ball points to; that guarantees that they will eventually reach a box that points to the box they opened at the start - containing the ball they're after
.

Changed to add spoileriness, because that's an actual answer if my base assumption is correct. It... for want of a better word - feels like the sort of solution a puzzle like this would want.

Edit2: ACTUAL SOLUTION, I THINK:
That assumption's not actually necessary. You don't need a single cohesive loop at the start; any loop that exists will give you the correct answer when you reach the end of it. The only problem - and the thing that requires the swaps - is if there are any loops longer than 100 boxes. Since there are at most two such loops - or one longer than 200 boxes - two swaps are enough to break those loops down into smaller-than-100-box ones. Then, as long as you start on the target number's box, you will eventually reach the correct ball in less than 100 boxes.
 
I think I got an idea, but can't arrive at solution for now.
Person 1 uses one of the numbers to tell how many boxes' numbers corresponds with ball number in it.
 
Going to be thinking of this until I fall to sleep, haha. I've thought of ways you could improve odds of finding any given number, but it's a convoluted method using ranges and a far cry from been able to guarantee a specific number can be found in 100 guesses. I'll see in the morning if it's possible I guess.
 
DragonSworne said:
Solved - At best it takes 3 questions if you are lucky. Use brute force to determine the occasional lair. Keep asking all of them which way one of them will say is the right direction. The person who changes their answer will be the occasional liar. Then apply the same logic used in the first riddle When you have figured out who occasionally lies.
Click to expand...

The random guy doesn't have to alternate his answers.

You could ask him a hundred times and he would say "left path" every time.
 
Obviously player 1 will put a ball in a particular box as to give player 2 some symbolic logic about how yhe balls are ordered. Say in box 150 he puts ball "20". Which could mean , all balls in the boxes lower when added together and divided out by number of boxes would give you the mean of that set.
 
I think I've actually solved the balls puzzle, filled in the last bit of inspiration I was missing. I've added the last bits to my previous post, and I think that fully works.

A further hint, for people who want to still plug away at it:

Player 1 is not imparting information to Player 2
 
mclem said:
I think I've actually solved the balls puzzle, filled in the last bit of inspiration I was missing. I've added the last bits to my previous post, and I think that fully works.

A further hint, for people who want to still plug away at it:

Player 1 is not imparting information to Player 2
Click to expand...
So which boxes do you swap?
 
mclem said:
I think I've actually solved the balls puzzle, filled in the last bit of inspiration I was missing. I've added the last bits to my previous post, and I think that fully works.

A further hint, for people who want to still plug away at it:

Player 1 is not imparting information to Player 2
Click to expand...

following your idea of n number of closed loops off less than 100 boxes, How does 2 knows if hé is in the good one?

Also, i don't think you can garantee the situation of the n-groups with 2 swaps
 
mamoui said:
following your idea of n number of closed loops off less than 100 boxes, How does 2 knows if hé is in the good one?
Click to expand...
Nvm that made no sense. But would swapping out numbers create smaller loops or just re arrange the one big one
 
mamoui said:
following your idea of n number of closed loops off less than 100 boxes, How does 2 knows if hé is in the good one?
Click to expand...
Every loop has less than 100 boxes, if he will follow the loop that starts with his number, he will reach his ball in less than 100 moves.
That said, this is a great task for player one - to ensure all dem loops! Feels like player 2 does nothing at all now.
 
kingwingin said:
So which boxes do you swap?
Click to expand...
(Explicit answer, hence spoilered. )

Player 1 studies the arrangement of boxes. If you assume each ball points to another box, you will get somewhere between 1 and 300 closed loops.

If all the loops consist of fewer than 100 boxes, player 1 does nothing.

If there is a loop consisting of more than 100 boxes, player 1 picks an arbitrary start point, remembers it, follows the loop for 100 boxes, and swaps the ball in the hundredth box with that in the first.

(It doesn't have to strictly be 100, it can be fewer as long as it splits into two even parts, but a loop longer than 200 boxes needs to be split into thirds instead, so 100 is a safe algorithmic shortcut.)

This is done at most twice, there can be no loops too long after that point.

Player 2 enters. He opens the box corresponding to the target number. He has now selected one of the loops, and we know there are fewer than 100 boxes in each.

He follows the loop around. In the final box, closing the loop, he'll find the ball that points to that first box. And the first box had the target number - so the ball that points to that first box... is the target ball.
 
GoodMorningPluto said:
Every loop has less than 100 boxes, if he will follow the loop that starts with his number, he will reach his ball in less than 100 moves.
That said, this is a great task for player one - to ensure all dem loops! Feels like player 2 does nothing at all now.
Click to expand...

You're right, that it. Worst case scénario, the initial state have two more than 100 loop or one 300 loop and 2 swaps will break it don to less than 100.
 
Dreavus said:
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.
Click to expand...

Not really. If I ask him what road to take, he will randomly decide on either yes or no.

So the truthful answer to "Would you answer yes if I asked you if I should go down the left road?" is "I don't know".
 
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