120 panthers and one goat are put on a magic island that only has grass. Panthers can eat grass, but they would rather eat goats. Assume: A. Each time only one panther can eat one goat, and that panther itself will become a goat after it eats the goat. B. All panthers are smart and perfectly rational and they want to survive. So will the goat be eaten? Show thought process.
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If the panthers do not know the result of eating the goat, the goat will be eaten exactly once.
That's not the question try again
Assuming you don't run out of grass: Goat never gets eaten.
1 goal of Panthers is to survive (can do that just by eating grass).
Becoming a Goat decreases survival chances.
Assuming you do run out of grass: Grass runs out. Panther closest to starvation eats goat. Process continues until you are left with one goat.
Sounds good to me
Let's do this by induction.
Suppose there is one goat and one panther. The panther will eat the goat.
Suppose there are two panthers and one goat. Neither panther will eat the goat. Because the first panther to eat the goat knows that it will get eaten soon after.
Suppose there are three panthers and one goat. The closest panther to the goat will eat the goat, because he'll know that once he becomes a goat, the two remaining panthers will not eat it.
Then, by continuation, if there are an even number of panthers, the goat will be left alone. If there are an odd number of panthers, the first panther will eat the goat. In this case, the goat will be left alone.
This is the correct answer to the problem. All other answers are wrong =)
worst answer ever.. better go edit it and make accounts to give yourself bananas..
ManBearPig~
While I'm normally against verbally felating someone on an online forum... I'll make an exception for you. Between this and that stupid post with that grade school math problem where you were the first to point out the question was ambigious, you have proven yourself to be one smart motherfucker. Though I can bet that a lot of it can be attributed to your background in mathematics.
Your answer makes me wish I had done more theoretical mathematics as an undergrad... +1.
No homo, Sayandarula
I think you are close, but wrong as well suppose there are an even number of panthers, eg 4 first panther eats the goat, but who will volunteer to eat that panther? knowing that whoever eats the panther will get eaten panther 1 eats goat panther 2 eats panther 1 panther 3 eats panther 2 panther 4 eats panther 3 panther 4 wins
but of course, all panthers will want to be panther 4, and no panther wants to be 1 or 2 or 3... so even if the number is even, i believe the panther can eat the goat and get away with it as well
you can try this logic with an odd number of panthers as well, every panther wants to be the last man standing, and it works out to a similar result as the even series
of course, the panther could also decide to not eat the goat
4 Panther example:
Panther: Damn i want to eat that goat Other Panther: Ya me too Panther: You eat it Other Panther: No way bro, if I do ull eats me instantly! Panther: No I won't; I'd get eaten Other Panther: Nah dude. If I eat, then you eat, only two kitties are left! Neither of them will eat you, and you still get goat meat!!! Panther: You got me foo'. Clever Panther.
Yep, this is the correct answer to this age old brainteaser.
Illini and man bear. I like where your heads at. Any one else with a diff answer or thought process
Because "all panthers are smart and perfectly rational", the goat will not be eaten. Why would a panther want to become a goat?
Alternatively, assuming the panthers are cool with becoming goats and assuming the original goat is pregnant and will give birth to a male goat... the goats will continue to mate (incestuously) and produce offspring until there are exactly 120 goats at which point all of the panthers will, at the same time, devour the goats.
...lol
It is impossible for the goat population to expand beyond one goat. If the goat is not eaten, he will remain until he dies naturally or runs out of grass. If a panther eats the goat, he becomes the goat leaving the population still at one. And the same process will repeat until the whole population is wiped out for the panthers.
The question is - do they know what happens when you eat the goat?
1) They know -> since they are rational and want to survive, they will eat the grass. 2) They do not know, but all of them see when one kills the sheep -> after eating the first goat, they will realize the consequences and since they want to survive, they will eat the grass only. 3)They do not know, and only one/few see when one kills the sheep -> various cases, ending up with someone eating the grass..
=> will goat get eaten? in 2 of 3 times yes
In all cases they end up eating the grass; New problem - is there unlimited grass?
1) There is -> problem solved. 2) There isnt -> they will kill the goat and each other until there is enough grass for the rest to survive.
=> will the goat be eaten? in 3 of 4 times yes
yes there's unlimited grass. its a big ass island
Interesting.....
I like MBP's answer, but why would a panther ever wanna be a goat? Goats suck. Panthers rock.
Goat wont be eaten. Fuck you goat.
The question boils down to an odd va even number of panthers. An even number will never eat the goat for fear of being eaten. An odd amount will always result in the goat being eaten.
Some good discussion on the thought process here.
Mondays are miserable enough already: when I see one of these and get sucked into the thread, it just makes life more difficult. Am I the only debbie downer who feels this way?
http://www.youtube.com/embed/SBedwedu01k?rel=0
No panther tho :(
BTW, Buddy, you never posted a follow-up answer to the Rubik's Cube question.
Idk if this has been said already, but since the Panthers are "are smart and perfectly rational and they want to survive" wouldn't they all do their best to eat all the grass they can before one tries to attempt to eat the goat (which would be a last resort).
After all the grass is consumed, one desperate panther will eat the goat, which will cause the the loss of one panther but the goat number still stays constant at 1. This cycle will continue, and at the end of the day, there will be exactly one panther and one goat on the island. Once the panther eats the goat, there will one goat on the island and it will eventually die of starvation since there will no more grass.
I would say 120 panthers remain and the single goat remains. Why?
OP states panthers are smart and rational. If a panther eats the goat, he is not behaving rationally, as even though he prefers to eat goats, it will turn him into one thereby decreasing his chances of survival.
OP says nothing about the panthers cannibalizing each other, thus the only way to ensure survival (albeit not as tasty) is to live off of grass and leave the goat alone.
Panthers are hunters and will never eat grass. So the strongest panther will eat the goat first. After the last panther turned to a goat, it will eat grass forever and die peacefully as an old goat.
I would like to know why my logic is wrong, there is still one goat left at the end of the feeding frenzy.
Well I guess I didn't think to define the size of the island. Maybe you'd be right if it was a tiny tiny island with little grass. When you think of an island i figured itd be, at elast, the size of Manhatten, where the goats and 120 panthers wouldnt really have to worry about running out of grass.
GRASS IS A WEED AND GORWS VERY QUICKLY. ESPECIALLY ON MAGIC ISLANDS.
The question is how smart and perfectly rational can a Panther be? I doubt that a Panther can resist his inner urges even more than humans can.
It has nothing to do with being smart and rational.
If the Panthers all know that no other Panther will eat the goat, then why not eat the goat and stay alive as a goat?
Here is the preference.
Staying alive > eating goat > eating grass
1 panther 1 goat - panther eats goat, since it gets to eat goat, which it prefers to eating grass and still gets to stay alive.
2 panthers 1 goat - neither panther will eat the goat because if it does, it will get eaten right after (i.e. the 1 panther 1 goat case)
3 panthers 1 goat - the panther that can get to the goat the fastest will eat the goat. Because once it becomes a goat, you're back to the 2 panther 1 goat case, in which neither panther will eat the goat.
and this continues ad infinitum
5 Panther Example:
Panther: Come here Goat! nom Other Panther: Your turn.... Goat/Panther: Go away. If u eats me, u die! (See the 4 Panther scenario) Other Panther: But grass is sooo bland.... Goat/Panther: Not to goats. Other Panther: Asshole
Moral of the story: Panthers don't die, but sometimes they turn into goats.
So the solution is two panthers and one goat.
I'd also say that with a very high uneven number of panthers, it is also very likely to be eaten even though according to manbearpig's logic, you shouldn't be eaten.
Think of this like the new planet of the apes movie where they get some brain serum or something. These panthers are fucking smart. That is why they are perfectly logical by definition
But assuming that the "two panther one goat" situation is valid ad infinitum is kind of irrational don't ya think?
How is it anything other than perfectly rational?
It is irrational because the ratio of goats to panthers is indefinitely smaller.
Not saying the pattern is affected but it's kind of stupid to make such a simplifying assumption.
One (fun?) point of skepticism for me is this:
Knowing whether to eat the goat/sheep/whatever it was requires not only knowing whether there are an even number of panthers or odd, but also knowing that all other panthers are aware of this information. Must be a huge clusterfuck when 120 panthers are running around trying to count how many other panthers there are and verify that all the other panthers have successfully done their counting correctly. Better safe than sorry..
Furthermore, the number of panthers seems unlikely to be stable. What if a panther is born or a panther dies? An even number of panthers sitting around eating grass seems like a pretty unstable equilibrium. I wouldn't risk it..
It doesn't matter if the panthers are aware of how many other panthers there are (although I agree with the even/odd outcome). The panthers are rational, and because they are rational, it is in their best interest not to eat the goat.
Survival is more important than eating better tasting food. There is no need to eat the goat other than hedonistic pleasure. While I believe manbearpig is correct regarding the outcome if an odd number of panthers are present, we know there are 120 and therefore no panthers will eat the goat.
NO. There was no specific constraint put on how high the Panthers were able to count, so you can't assume that they would have trouble determining the number of other Panthers.
And what's this about panthers dying and being born? If I told you that there were 10 people in a room and another 5 entered, would you have to ask how many people died to tell me the answer was 15?
NOT THAT HARD PEOPLE.
illiniPride - dude you deserve a medal for the patience you've demonstrated in this thread.
On a side note - how is this 'debate' still going on?
Patrick, can we start having minimum IQ requirements before people are allowed to sign up for WSO? I know it'll reduce traffic, but it will greatly improve quality ( =P only half serious)
RagingonCaffeine #FinalsWeek
Side note: I still can't believe how easily everyone is distracted by the grass. Stealth troll is stealth
Side side note: I thought the beancounter was trolling. Turns out he is just an accountant who doesn't know better.
Turns out bearpig and illinoispride are just non-targets.
the answer depends on whether the panthers believe in goat jesus. if so, bon appetit.
I agree w/ IlliniPride's answer. Without further constraints on the grass, no rational panther will give his life to eat, unless there are only three panthers. So:
2 Panthers: no eat 3 panthers: eat 4 panthers to infinity panthers: no eat 120 panthers: no eat
I assume their utility function values life more than eating the goat, and the grass is unlimited.
edit: woops double post
You also assume law of conservation of panthers (panthers are neither created nor destroyed, only optionally transformed into goats). I am still on the fence about whether this is a fair assumption. It's clear that the question intends to impose this constraint, but it's so well known that animals can procreate/die that it ruins the question for me.
I realize this is nitpicking at second order effects while so many monkeys are still failing to reach the easy conclusion of the straightforward interpretation of the question.. But the solution to the brainteaser without considering possible complications just requires so little thought.
Problem is solved, yet shitshow ensues. THIS...IS...WSO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
it would be a more interesting problem if goats were not conserved. it would be even MORE interesting if we had two subcases of the goats obeying fermi or bose statistics. in the first case you have basically LIFO accounting of the marginal goat being consumed but only one goat per time step consumable. in the latter case you have indistinguishable goats all subject to consumption all at once, where the goats consumed is bounded only by the number of panthers.
ok you smart motherfuckers figure it out.
Since the final result is no grass and 1 goat, the goat will die without the grass. Everyone's fucked. They should all try their swimming skills, because that alone will give them the best chance of survival.
P.S. mrbeancounter, you are an idiot.
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