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Topic: Easy: Knight and Dragon (Read 19351 times) |
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Re: Easy: Knight and Dragon
« Reply #25 on: Nov 12th, 2002, 12:45am » |
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If anyone is concerned about pure water being used, why couldn't the knight have brought some water with a mixture of wells 1 and 2?
He must have some way of drinking water and not dying. I don't see how mixing the water in a cup and in a stomach is very diffrent. If you want I'll add that water was poured into the cup from well one first and then water from well two was added after.
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Re: Easy: Knight and Dragon
« Reply #26 on: Nov 13th, 2002, 12:37am » |
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All of your answers are just hypothetical, and it doesn't have any real proof. In conclusion, I do believe that there is no wrong answer for this question. Unless, you give a really dumb answer. 
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Sylvie Tsie
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Re: Easy: Knight and Dragon
« Reply #27 on: Nov 26th, 2002, 6:56am » |
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You're all wrong.
The knight drinks from Wel number one, and brings normal water. Because the knight has honor.
The dragon is a sly creature, and brings water one to seven. And poisons the knight.
Then
The knight kills the dragon, because duels only end after someone dies.
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TenaliRaman
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Re: Easy: Knight and Dragon
« Reply #28 on: Jun 6th, 2003, 11:29pm » |
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Of all the above solution which one is right  (i can't make out)
But the solution provided James G seems appropriate and seems to be within the constraints of the problem.
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Icarus
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Re: Easy: Knight and Dragon
« Reply #29 on: Jun 7th, 2003, 2:29pm » |
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There is no single "right" answer to this riddle. As has been shown (I think in this thread, though I didn't see it in my quick scan - but it may be in one of the other threads for this riddle), both the knight and the dragon can insure their own survival. That the dragon dies tells you that he didn't figure out how. Thus it becomes a matter of choosing which of the many errors possible is the one that the dragon makes.
The real puzzle here is to figure out how the knight can survive (the "preemptive self-poisoning" trick). Once you know that, then you can come up with a number of scenarios that match the puzzle.
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TenaliRaman
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Re: Easy: Knight and Dragon
« Reply #30 on: Jun 8th, 2003, 9:17am » |
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on Jun 7th, 2003, 2:29pm, Icarus wrote:
The real puzzle here is to figure out how the knight can survive (the "preemptive self-poisoning" trick). Once you know that, then you can come up with a number of scenarios that match the puzzle. |
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I quite realised that when i was working with the problem but i was simply searching for the scenario which remains very much inside the frame of the question.
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Icarus
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Re: Easy: Knight and Dragon
« Reply #31 on: Jun 8th, 2003, 8:42pm » |
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on Jun 8th, 2003, 9:17am, TenaliRaman wrote:| I quite realised that when i was working with the problem but i was simply searching for the scenario which remains very much inside the frame of the question. |
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And what I am saying is that there are MANY scenarios which remain very much inside the frame of the question.
The one thing they have in common is that the Knight pre-poisons himself. Beyond that there is a great deal of freedom inside the frame of the question to create plausible courses of events.
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TenaliRaman
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Re: Easy: Knight and Dragon
« Reply #32 on: Jun 8th, 2003, 9:46pm » |
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Ofcourse! Cheers!!! 
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Lillith
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Re: Easy: Knight and Dragon
« Reply #33 on: Sep 18th, 2003, 3:38am » |
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Well, if any of both drinks water of well, let's say,1 and after that,to cure himself, well 2, doesn't he get poisoned by well 2 that way? And if this is so, the knight can give any water to the dragon to kill the beast and just NOT DRINK THE WATER the dragon gives to him. Correct
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Icarus
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Re: Easy: Knight and Dragon
« Reply #34 on: Sep 18th, 2003, 3:34pm » |
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When I first read this puzzle, I thought the same thing. The puzzle is not well-stated in my opinion. But reading the discussion, it becomes clear that the INTENT was: if you are poisoned by a lower number well, drinking water from any higher well will cure you, not poison you. It is only when you are not poisoned already that the higher numbered well water will poison you.
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TuCelts
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Re: Easy: Knight and Dragon
« Reply #35 on: Nov 6th, 2003, 10:56pm » |
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I rather feel that the INTENT of this brain teaser (not a true puzzle since it has no concrete solution) was to mislead and or to tease people mercilessly. If you begin by looking at the stated facts you see several gaps. Facts, as stated, are:
a dragon and knight reside on one island; there are 8 sources of liquid including the 7 poisonous wells and the liquid around the island; each poisonous well can be cured only by the liquid of a higher well, indicating that well 1 is cured by all others and 7 is cured by none; only the dragon can reach well 7; the knight and dragon both bring a glass of water; both duellists drink from the other's glass; the dragon dies. Everything else is done on an assumption. Try assuming that there isnt even water in the wells, as the "puzzle" never said what kind of well they are. Assume, for the fun of it, that they are oil wells  . The water comes from another source and the duel is a physical contest and knight kills dragon. Or, again just for the fun of it, assume the water is safe, or they took precautions as suggested by some. The duel ends in a draw, and the dragon flies away to his mountainous home, and accidentally drinks from well 7, poisoning himself. At this point there are only two real questions left: 'How many ways can I work this out?' and 'How long will people keep debating the relative merits of the various points of view?'.
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simX
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Re: Easy: Knight and Dragon
« Reply #36 on: Apr 11th, 2004, 2:44am » |
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There's one thing I'd like to point out for all of those that think bringing a mix of any two wells will do the trick.
Consider: drinking first from well 1 poisons, then drinking from well 2 cures. But when drinking first from well 2 poisions, drinking from well 1 afterwards does NOT cure. But if you assume that the cure happens simply by neutralizing of the two poisons in the stomach by mixing, then you'd have to conclude that drinking from any well will cure the poisoning from any other well (which is clearly a contradiction from the riddle).
(You COULD say that there's some fundamental difference between pouring water from well 1 into water from well 2 and pouring water from well 2 into well 1 such that only the former will create benign water, but I think that's way too far fetched even for some of the suggestions in this thread. )
Stated another way: since drinking first from 1 then from 2 leaves you alive, but drinking first from 2 then from 1 leaves you dead (assuming you don't do anything else), the cure cannot possibly come from mixing since if it did, both situations would leave you alive.
So the assumption that the curing happens by mixing in the stomach is a fallacy. Therefore, I believe that the only reasonable solution to the problem involves the knight bringing benign water that comes from around the island, not from any of the wells.
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towr
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Re: Easy: Knight and Dragon
« Reply #37 on: Apr 11th, 2004, 7:32am » |
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on Apr 11th, 2004, 2:44am, simX wrote:| But if you assume that the cure happens simply by neutralizing of the two poisons in the stomach by mixing, then you'd have to conclude that drinking from any well will cure the poisoning from any other well (which is clearly a contradiction from the riddle). |
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Actually, no. If neutralization happens just by mixing, you must conclude that if A neutralizes B, then B neutralizes A, and not that they all neutralize each other.
It's still a contradiction, but a weaker one.
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simX
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Re: Easy: Knight and Dragon
« Reply #38 on: Apr 11th, 2004, 1:04pm » |
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on Apr 11th, 2004, 7:32am, towr wrote:
Actually, no. If neutralization happens just by mixing, you must conclude that if A neutralizes B, then B neutralizes A, and not that they all neutralize each other.
It's still a contradiction, but a weaker one. |
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But by extension, you can apply this to all pairs of wells. Given any pair of wells, one well will have a higher number and therefore neutralize the lower one. But if neutralization happens by mixing, then the lower one would also neutralize the higher one.
So since we can extend this fact to all pairs of wells, it means that any well can be neutralized by any other well.
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towr
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Re: Easy: Knight and Dragon
« Reply #39 on: Apr 11th, 2004, 2:42pm » |
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on Apr 11th, 2004, 1:04pm, simX wrote:| But by extension, you can apply this to all pairs of wells. |
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doh, sorry.. I thought you needed the next higher well (x+1) to cancel the poison (x). But any higher numbered well seems to do the trick..
I'm really doing a particularly bad job at reading the problems today it seems..
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rmsgrey
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Re: Easy: Knight and Dragon
« Reply #40 on: Apr 19th, 2004, 5:14am » |
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One possible mechanism to account for the higher-number antidote phenomenon would be the "water" from each well containing an active ingredient that breaks down over time - the break-down product is toxic, and the initial state non-toxic, and the intial state of any higher numbered well reacts with the breakdown product of any lower numbered well to neutralise both (in such a way that proportions needn't be exact)
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Grimbal
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Re: Easy: Knight and Dragon
« Reply #41 on: Apr 22nd, 2004, 3:26pm » |
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If the dragon is allowed to go drinking after the duel, he just drinks the water that is given to him. Then, he goes drink from well 6, well 6 again and well 7. If the knight's water is from well 1 to 5, then well 6 cures him, then 6 poisons him again and 7 cures him. If the water was from well 6, well 6 doesn't cure him and well 7 cures him. If the original water was clear, well 6 poisons him and well 7 cures him.
So, it seems they are not allowed to drink afterwards.
But then, whoever brings water from well 1 kills his opponent. If they are healthy, it will poison them. If they are not, it will not cure them.
So there is not solution.
It would make sense if they switch glass twice. They bring water, switch glasses, drink, switch again and drink again. It is like a contest of who can provide the more powerful water.
Then what happened is that the dragon brought water from well 7, thinking he could not be beaten, while the knight, realizing that it wouldn't do, decided to drink water from well 1 and then brought a glass of normal water.
Of course, the dragon is stupid.
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Grimbal
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Re: Easy: Knight and Dragon
« Reply #42 on: Apr 22nd, 2004, 3:30pm » |
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PS: assuming that the dragon is stupid leads to other silly solutions:
The dragon did not realize that the glasses would be switched and brought clear water, while the knight brought water from well 1 because it was on the way to the duel arena.
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Icarus
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Re: Easy: Knight and Dragon
« Reply #43 on: Apr 22nd, 2004, 3:42pm » |
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If you read through the whole thread (or it might be in one of the other threads for this puzzle), you will see that it has already been figured out how both the Knight and the Dragon can guarantee their own survival. So the fact that the Dragon dies indicates he wasn't the brightest of lights.
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kevincmann
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Re: Easy: Knight and Dragon
« Reply #44 on: Jul 31st, 2004, 2:38pm » |
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I think the solution is that the Knight drank some lower level water before the duel, therefore having the well 7 water cancel out the poison instead of being the poison. The dragon, otherwise, could not prepare in the same way because 7 is the highest. This is of course under a few assumptions, one being that the duel is an organized event in which they exchange water and sees who dies (which sounds silly).
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Icarus
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Re: Easy: Knight and Dragon
« Reply #45 on: Aug 5th, 2004, 11:32am » |
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on Jul 31st, 2004, 2:38pm, kevincmann wrote:| The dragon, otherwise, could not prepare in the same way because 7 is the highest. |
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The dragon can prepare in the same way. He has access to all 7 wells, so he can drink from anyone of them. Somewhere in this thread or another for the same riddle, someone has stated what each must do to be assured of survival under all circumstances (that is, under all possible combinations of water from the 7 wells).
This assumes that the amount of water drunk from the wells is not crucial:
1) Before the contest, the contestant (knight or dragon) drinks from well #1.
2) At the contest, he drinks the water brought by his opponent. If the water was from a higher numbered well, he is cured. If the water was either from well #1 or was ordinary water, he is still poisoned by well #1 water.
3) After the contest, he goes back to well 1 and drinks again. Now he is definitely poisoned by well #1 water.
4) He goes to any higher-numbered well and drinks, curing the poisoning.
Since the dragon died, it is evident that he did not figure this out. That the knight lived either means that he followed this procedure or some variant, or was simply lucky enough that the dragon didn't bring water from well #1.
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colby wallace
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Re: Easy: Knight and Dragon
« Reply #46 on: Aug 20th, 2004, 6:54am » |
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You people are not getting the rules to the original actual
riddle. Here's the real skinny on this:
A dragon and a knight lived in a valley. In this valley there
were six poison wells on the side of a mountain. The wells
contained a very strange kind of poison. If you drank from a
lower level well, you would die unless you drank from a
higher-level well within two minutes after drinking.That is
to say, if you drank from the first well, you could save
yourself by drinking from the second, third, fourth, fifth,
or sixth. If you drank from the fifth well, you could only
survive by drinking from the sixth well.
Both the knight and the dragon could get water from the first
five wells, but only the dragon could get water from the sixth
well because it was so high up. One day, the knight and the
dragon got tired of sharing the valley and decided to have a duel.
The rules of the duel:
They would each bring two glasses of water and give one glass
to the other. And then the other would have to drink it.
Then they would the second glass, which they brought for themselves.
On the day of the duel, the knight and the dragon met.
They exchanged glasses and drank the water in the glasses.
Then they drank the water in their second bottle.
The dragon died and the knight lived. Why?
The canonical answer forthcoming...
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colby wallace
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Re: Easy: Knight and Dragon
« Reply #47 on: Aug 20th, 2004, 7:16am » |
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The canonical answer.
Oh, BTW, the only water available in the valley is from
the poisoned wells. There is no other water. That's
part of the rules. Here we go...
Remember, there is no antedote for the top well's water.
The top well's water is also the antedote for anything the
the Knight could give to the dragon. So one would think...
The dragon, thinking this, brings two glasses from the top
well thinking, "I will give the knight something that has
no antidote!" He is also thinking, "Whatever the Knight
gives me, I have the antidote for!"
So far, this is how most everyone thinks of this.
It would appear that the Knight has no recourse...
The Knight, preparing for this, drinks from well #1, or the
lowest level well before the duel. He arrives at the duel
already poisoned... he then drinks the *antidote* for
what he already has in his system, the top well's water
from the dragon.
That's well and good, but what does he drink now?
And what does he give to the dragon. Aaaah... glad you asked.
Since there is no "pure" water, the Knight makes some,
two glasses full of it, by getting two half glasses from
well #1 (the lowest well) and then adding water from
well #2 to each glass. He brings these two placebo
concoctions to the duel. When he drinks from his own
glass, he is fine. He also gives a placebo to the dragon,
who then proceeds to drink from his own #6 (highest well)
glass, thus poisoning himself in a way that has no antedote!
Now, you may say that the dragon could double-cross-
counter-think of this possibility and also poison himself before
arriving, and then in response the Knight could... and the
dragon could also, knowing what the Knight will probably do,
bring #1 well water for the Knight to drink...
You get the picture.
There is no way to *insure* one's survival actually.
In reality, it is an elaborate game of one upsmanship,
not unlike the "odds/evens" game one played as a kid
where you would put out 1 or 2 fingers simultaneously
with a friend and if there are an odd number of total
fingers, you win, evens you lose.
Still, I have provided the canonical answer, flawed as
it is.
Good day to you all and have a happy.
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Icarus
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Re: Easy: Knight and Dragon
« Reply #48 on: Aug 20th, 2004, 8:29am » |
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You might want to consider a few things, colby.
1) Your version of the riddle is not the same as that posted, and to which everyone has replied. If you change the riddle, you have no right to dismiss earlier comments for failing to conform to your version.
2) Even given the differences in the versions, the discussion on this riddle (which occurs in several threads, so some of what I am refering to may not be in this particular thread) has covered a significant number of variations, including yours. You will find that your "canonical solution" has already been given - including the creation of unpoisoned water from mixing the water of two wells.
3) The procedure I outlined in the post before yours still guarantees survival, provided the contestants bring the extra water with them to drink right before and after the contest, before they succomb to the poisoning (your version has to allow this, as your solution still requires the knight to poison himself before the contest begins).
If you demand a match in the amount of water drunk from higher and lower-numbered well to exact a cure, then the contestent must judge how much water to drink by their condition. I.e. if the drink a glass of "curative" water, but are still poisoned, they know that the other must have given them well #1 water, and so they need another glass. If they can't accomplish this, then they would have died long ago, since only poisoned water is available to them.
The only way the contestants can prevent such a ploy is to ensure each does not get away to go drink something else in the 2 minutes after the exchange. But if they are smart enough to recognize the need for this, why would they not also be smart enough to simply wait 2 minutes before exchanging the first glass. If the dragon did this, the poor knight would die from his pre-poisoning before the official duel began!
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rmsgrey
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Re: Easy: Knight and Dragon
« Reply #49 on: Aug 20th, 2004, 11:22am » |
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There's also the question of how mixing creates pure water - how can the water in a glass tell whether its well 1 water to which well 2 water has been added, or well 2 water to which well 1 water has been added?
While I have proposed a mechanism whereby the water can tell in which order you drink it, by breaking down in your body, I can't think of a way for water stored in a glass to tell. Of course, if it's all magic, then of course it could work, but in that case you should mention explicitly that you can neutralise water by mixing it outside the body if that fact is important to the intended solution
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