(The scenario will be presented in first person, to get rid of the ambiguity of the "all-knowing third-person")
Scenario: I and 50 of my best friends, relatives, and people I trust, are standing around 2 empty cup in my kitchen. A man (I do not recognize him) walks into the kitchen, holding a vacuum sealed package containing one of these cyanide test kits. He then proceeds to fill up both glasses with water from my sink, take a pill out of his pocket, and drops it in the left cup. He then uses a cyanide test strip in the left and right cups- the one on the left comes up positive, while the one on the right comes up negative. He then tells I, and the 50 people around me, that we must drink from one of the cups, or he will kill all of us. The 50 people around me go first, and they all drink from the left cup, the cup I saw the cyanide pill go in. They all then turn to me, and tell me to drink from the left cup. I am not given the opportunity to ask them why. Edit: For arguments sake, let's assume it takes an hour to see the effects of cyanide poisoning.
Question: Which cup should I drink from, if I want to survive? Follow-up Prove that you should drink from that cup. You can use any logical system, or any other probabilistic analysis- but you cannot simply say "There's a better chance to survive drinking from cup X"
I was arguing this out with a couple of friends for hours, but since none of us can really appeal to an argument constructed from premises we all agree on, we weren't able to convince each other. More than I would want to hear that I am correct, I would want to be shown definitively which answer is correct
This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
The truthfulness of the cyanide pills and the cyanide strip cannot be verified. The mysterious man could be lying, or could be using faulty pills/strips. You can't know for certain.
The fact that your bros didn't die can be verified.
Probably wait like 10 minutes in case it takes a while for the cyanide to kick in. If no one dies, grab the other cup and throw it at the dude's face.
Drink from the right... it has no unknowns assuming everything to be told is told and there was no "you didn't notice he dropped a mysterious powder in the right cup"
The cup was in your kitchen, so I'd assume it was your cup that you know where it came from and where it has been. The water is from your sink and the man did nothing with it.
With the rather absurd nature of the question, I don't know if the time factor can really be played... but as people above have mentioned, if the first person is not dead yet by the time a 50th drinks... it is either not cyanide or the miniscule amount you actually get from less than 1/50th a cup of water is not life threatening. However, this method still presents unknowns... and even more of them than if you had been the first to drink because now 50 people have touched that cup while leaving the right one perfectly alone.
Both cups are poisoned. I've seen this movie before.
The left cup is poisoned with some non-cyanide poison that was on the test strip, perhaps a slower acting one to give people the illusion that they're safe, while the right cup is poisoned with cyanide.
If he's gone to the trouble of getting a cyanide pill, him re vacuum sealing the cyanide test kit after poisoning it would not be out of the question.
Moral of the story: Never mess with a Sicilian when death is on the line
On February 05 2014 11:37 Mothra wrote: This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
You saw all 50 people watching the same thing you did. You don't have enough time to see whether the 50 will drop dead or not- let's assume cyanide takes an hour to show effect, or something. And it's hypothetical, so you're confusion about the circumstances should be taken into account in your answer.
On February 05 2014 11:43 lichter wrote: The truthfulness of the cyanide pills and the cyanide strip cannot be verified. The mysterious man could be lying, or could be using faulty pills/strips. You can't know for certain.
The fact that your bros didn't die can be verified.
Probably wait like 10 minutes in case it takes a while for the cyanide to kick in. If no one dies, grab the other cup and throw it at the dude's face.
Fine, fine, I'll add that you don't have enough time to see what happened...
I don't get it. If he didn't do anything to the cup on the right and it tested negative, shouldn't it be ok? Even if other people use the cup on the left, it still tested positive for cyanide and was tampered with... I don't see any reason to drink the left cup with the given information.
Is this a logic game or merely a hypothetical? If it's a logic game either it is really simple or I am missing something - however, I wouldn't say I'm missing something if you say "he put something in it while you weren't looking" or "the testing kit was broken!" I am curious now.
On February 05 2014 11:37 Mothra wrote: This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
You saw all 50 people watching the same thing you did. You don't have enough time to see whether the 50 will drop dead or not- let's assume cyanide takes an hour to show effect, or something. And it's hypothetical, so you're confusion about the circumstances should be taken into account in your answer.
50 people watched him put pill in left cup, do positive cyanide test on it, do nothing to the right cup but fill it with water, and they all drink the from the left cup? Again, is there any reason why you wouldn't choose a cup which you saw was only filled with water over one that some guy put a pill in, even without the cyanide test? I feel like you are missing part of your hypothetical.
I would first ask all those people why the fuck they would drink from the left glass. If they really are close friends and had a reason to do so, they would tell me.
Because you can be paranoia at multiple levels here, nothing one would think of would be waterproof. If there really is no way to tell if your friends are okay, it doesnt matter which cup you drink. Any further estimation would be based on unknown parameters. Though in practice, i'd probably be too stressed out to think straight, not believe my own eyes anymore, and drink the poisoned glass.
I think it's more interesting when you don't know anything (pills put in glasses or not etc) and just have to randomly choose one of two glasses, knowing all your friends chose one particular glass and that only one glass (unknown to you or your friends) is poisonous. Would you go along and all live or all die? Or would you take the risk to die or live alone?
On February 05 2014 11:37 Mothra wrote: This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
You saw all 50 people watching the same thing you did. You don't have enough time to see whether the 50 will drop dead or not- let's assume cyanide takes an hour to show effect, or something. And it's hypothetical, so you're confusion about the circumstances should be taken into account in your answer.
50 people watched him put pill in left cup, do positive cyanide test on it, do nothing to the right cup but fill it with water, and they all drink the from the left cup? Again, is there any reason why you wouldn't choose a cup which you saw was only filled with water over one that some guy put a pill in, even without the cyanide test? I feel like you are missing part of your hypothetical.
Why would the 50 people drink from the left cup, if not for the fact that they think something that you aren't thinking about?
On February 05 2014 11:37 Mothra wrote: This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
You saw all 50 people watching the same thing you did. You don't have enough time to see whether the 50 will drop dead or not- let's assume cyanide takes an hour to show effect, or something. And it's hypothetical, so you're confusion about the circumstances should be taken into account in your answer.
50 people watched him put pill in left cup, do positive cyanide test on it, do nothing to the right cup but fill it with water, and they all drink the from the left cup? Again, is there any reason why you wouldn't choose a cup which you saw was only filled with water over one that some guy put a pill in, even without the cyanide test? I feel like you are missing part of your hypothetical.
Why would the 50 people drink from the left cup, if not for the fact that they think something that you aren't thinking about?
On February 05 2014 11:37 Mothra wrote: This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
You saw all 50 people watching the same thing you did. You don't have enough time to see whether the 50 will drop dead or not- let's assume cyanide takes an hour to show effect, or something. And it's hypothetical, so you're confusion about the circumstances should be taken into account in your answer.
50 people watched him put pill in left cup, do positive cyanide test on it, do nothing to the right cup but fill it with water, and they all drink the from the left cup? Again, is there any reason why you wouldn't choose a cup which you saw was only filled with water over one that some guy put a pill in, even without the cyanide test? I feel like you are missing part of your hypothetical.
Why would the 50 people drink from the left cup, if not for the fact that they think something that you aren't thinking about?
Like suicidal thoughts?
What are the chances that those 50 people all have suicidal thoughts, relative to the chance that they know something you don't, even though what you saw was really obvious?
On February 05 2014 11:37 Mothra wrote: This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
You saw all 50 people watching the same thing you did. You don't have enough time to see whether the 50 will drop dead or not- let's assume cyanide takes an hour to show effect, or something. And it's hypothetical, so you're confusion about the circumstances should be taken into account in your answer.
50 people watched him put pill in left cup, do positive cyanide test on it, do nothing to the right cup but fill it with water, and they all drink the from the left cup? Again, is there any reason why you wouldn't choose a cup which you saw was only filled with water over one that some guy put a pill in, even without the cyanide test? I feel like you are missing part of your hypothetical.
Why would the 50 people drink from the left cup, if not for the fact that they think something that you aren't thinking about?
Basically the only relevant details are that one cup contains tap water, the other has the same tap water plus an unknown pill. There's really no question unless there's some hidden "haha gotcha" secret. Pretty sure you forgot or messed up some detail of the scenario that would have made it an interesting choice.
On February 05 2014 11:37 Mothra wrote: This doesn't make sense to me... are you saying you're the only one that saw the pill go in and the cyanide test? If the 50 people drank from the cyanide cup shouldn't they be dropping dead? Why did all 50 drink from the left cup and why are they asking you to drink from it? I don't see any reason why you couldn't just drink from the right cup and live.
You saw all 50 people watching the same thing you did. You don't have enough time to see whether the 50 will drop dead or not- let's assume cyanide takes an hour to show effect, or something. And it's hypothetical, so you're confusion about the circumstances should be taken into account in your answer.
50 people watched him put pill in left cup, do positive cyanide test on it, do nothing to the right cup but fill it with water, and they all drink the from the left cup? Again, is there any reason why you wouldn't choose a cup which you saw was only filled with water over one that some guy put a pill in, even without the cyanide test? I feel like you are missing part of your hypothetical.
Why would the 50 people drink from the left cup, if not for the fact that they think something that you aren't thinking about?
Basically the only relevant details are that one cup contains tap water, the other has the same tap water plus an unknown pill. There's really no question unless there's some hidden "haha gotcha" secret. Pretty sure you forgot or messed up some detail of the scenario that would have made it an interesting choice.
Maybe there is some hidden "haha gotcha" secret. And you have some reason to believe that that exists, because that would possibly be the simplest explanation as to why the 50 people drank from the left.
On February 05 2014 14:37 lichter wrote: seriously, throwing both glasses at the crazy dude is the best option
lol, I like how you came back to reiterate your point
Well, it is to prove the point that the hypothetical situation you present is so open ended with unknown variables and loose ends that it is possible to really do anything you want without arriving at a 'true' right answer. So far you, as the presenter of the premise, have added information slowly every time someone suggests a solution.
Ask the 50 dudes why they drank it? Nope they aren't telling you for some reason.
Wait for the 50 dudes to die or react? Nope you have to drink immediately for some reason.
Confirm the veracity of the cyanide pill or cyanide test? Nope can't do that either for some reason.
When a premise is not water tight there is no answer.
So just throw the poison at his face because the guy is obvs a jerk.
Given that this man has done nothing to indicate that he is capable of fulfilling his thread to kill all of us, I'd probably say to skip drinking out of either cup and call 911. (although, knowing myself and my friends, if that situation actually arose, I would probably think it some elaborate practical joke.)
You guys are not reading the situations properly. You're not supposed to solve this, you're supposed to say what you would do, and it tells you about your character. You guys have hung out in the mathematical quiz thread too much, looking for a definite answer when there can't be one.
Personally, I would drink from the right glass. I would have no reason to believe my friends know something I don't, and I trust my own perception. Unless I somehow fucked up when the pill was inserted, I should be fine. Sad that 50 of my friends are dying, but otherwise fine.
Unless, of course, the 50 people drinking from the left glass left it empty, that would be a good time to "drink" from it.
(Though, the OP does say he want to be proven definitely "correct", which is dumb since the scenario has no "correct" solution, it's all lateral thinking.)
On February 05 2014 13:03 DarkPlasmaBall wrote: The answer is: It doesn't matter because you've spent years building up a resistance to iocane powder cyanide.
This is what I was thinking. Not all 50 of your friends need be suicidal; only one of them does, or has to be acting irrationally on account of the stress of the situation. Let's say either one of these is true, and the first friend drinks from the left glass, which tested positive for cyanide.
Any rational person would assume that the first friend would be doomed to death by poison. Why, then, do the other 49 also drink from the same poisonous glass? Is it perhaps that they cannot bear the thought of living without the first friend, as the second drinker is the first's spouse or significant other, and the third is the second's mistress, and the fourth is the third's stalker, and the fifth is the fourth's mother, and the sixth is the fifth's husband, and so on?
Naturally, if one is aware that the cyanide's effects will not be made clear until after the drink has been chosen, they should choose the right glass. Drinking the water that tested positive for cyanide just because everyone else did it, and appears to be fine seconds later, while the poison could in fact be coursing through their veins, ticking down the time they have remaining, is suicidal.
If they all know something you don't, but you can't ask them whether they do, then it is still in your best interest to drink the glass that tested negative, because it is impossible to know whether they have been acting rationally, which the first drinker clearly hasn't, and thereby reasonably come upon the conclusion that the glass that tested positive is safe to drink.
How do we know what the test results were, anyway? Are we certain that one result is different from the other? You said the cyanide takes time to have an effect, yet there is one positive result and one negative. Does this mean that the cyanide test reacts immediately, and people do not?
EPT
