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Monday Morning Braintease
 

Buddyfox's picture
O
 
Points)
 on 5/7/12 at 12:55pm
panther.jpg

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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Unforseen's picture

If the panthers do not know

(King Kong, 1,099
 
Points)
 on 5/7/12 at 8:50am

If the panthers do not know the result of eating the goat, the goat will be eaten exactly once.

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Buddyfox's picture

That's not the question try

O
 
Points)
 on 5/7/12 at 9:12am

That's not the question try again

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illiniPride's picture

Assuming you don't run out of

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 9:33am

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.

Leadership can be defined in two words: "Follow Me"

Ultima-RDK's picture

illiniPride: Assuming you

CD
(Orangutan, 305
 
Points)
 on 5/7/12 at 9:38am
illiniPride:

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

Sometimes lies are more dependable than the truth.

manbearpig's picture

Let's do this by

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 9:42am

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.

-MBP

Buddyfox's picture

Illini and man bear. I like

O
 
Points)
 on 5/7/12 at 9:47am

Illini and man bear. I like where your heads at. Any one else with a diff answer or thought process

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Poff's picture

Because "all panthers are

(Baboon, 152
 
Points)
 on 5/7/12 at 10:00am

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.

Ultima-RDK's picture

Poff: Alternatively, assuming

CD
(Orangutan, 305
 
Points)
 on 5/7/12 at 10:15am
Poff:

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

Sometimes lies are more dependable than the truth.

madmoney15's picture

It is impossible for the goat

(Orangutan, 331
 
Points)
 on 5/7/12 at 10:26am

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.

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Dimethyltryptamine's picture

The question is - do they

(Baboon, 110
 
Points)
 on 5/7/12 at 10:31am

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

Buddyfox's picture

yes there's unlimited grass.

O
 
Points)
 on 5/7/12 at 11:37am

yes there's unlimited grass. its a big ass island

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illiniPride's picture

Buddyfox: yes there's

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 11:41am
Buddyfox:

yes there's unlimited grass. its a big ass island

So magic island = "magic grass?" And then panthers start turning into goats?

Interesting.....

Leadership can be defined in two words: "Follow Me"

manbearpig's picture

illiniPride: Assuming you

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 12:13pm
illiniPride:

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.

This is a tangent to the actual question. In brainteasers, you cannot impose your own assumptions on the scenario in question. In this case, there is no specific constraint on the quantity of grass, so you can't use an assumption about a limited supply in your solution to the problem.

-MBP

manbearpig's picture

manbearpig: Let's do this by

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 12:16pm
manbearpig:

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 =)

-MBP

illiniPride's picture

manbearpig: illiniPride: As

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 12:24pm
manbearpig:
illiniPride:

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.

This is a tangent to the actual question. In brainteasers, you cannot impose your own assumptions on the scenario in question. In this case, there is no specific constraint on the quantity of grass, so you can't use an assumption about a limited supply in your solution to the problem.

Its more fun to try and break the question. Besides, a good brainteaser shouldn't be ambiguous IMO.

Leadership can be defined in two words: "Follow Me"

manbearpig's picture

illiniPride: manbearpig:

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 12:28pm

-MBP

Dimethyltryptamine's picture

worst answer ever.. better go

(Baboon, 110
 
Points)
 on 5/7/12 at 12:29pm
manbearpig's picture

Dimethyltryptamine: worst

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 12:33pm

-MBP

BlackHat's picture

I like MBP's answer, but why

HF
 
Points)
 on 5/7/12 at 12:52pm

I hate victims who respect their executioners

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Dimethyltryptamine's picture

I'm not sure if you are

(Baboon, 110
 
Points)
 on 5/7/12 at 12:58pm
illiniPride's picture

manbearpig: illiniPride:

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 1:05pm

Leadership can be defined in two words: "Follow Me"

illiniPride's picture

Dimethyltryptamine: I'm not

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 1:09pm

Leadership can be defined in two words: "Follow Me"

manbearpig's picture

Dimethyltryptamine: I'm not

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 1:20pm

-MBP

go.with.the.flow's picture

Goat wont be eaten. Fuck you

EN
(King Kong, 1,109
 
Points)
 on 5/7/12 at 1:22pm

|| But feeling good and enjoying life are prerequisites to success, not by products of it- Midas Mulligan Magoo ||

Buddyfox's picture

The question boils down to an

O
 
Points)
 on 5/7/12 at 1:32pm

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Dimethyltryptamine's picture

1) ok 2)

(Baboon, 110
 
Points)
 on 5/7/12 at 1:36pm
manbearpig's picture

Dimethyltryptamine: 3)

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 1:44pm

-MBP

sayandarula's picture

manbearpig: Let's do this by

O
(King Kong, 1,809
 
Points)
 on 5/7/12 at 1:57pm

Money Never Sleeps? More like Money Never SUCKS amirite?!?!?!?

Dimethyltryptamine's picture

1) Nope, you cant say that

(Baboon, 110
 
Points)
 on 5/7/12 at 2:00pm
illiniPride's picture

Dimethyltryptamine: worst

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 2:01pm

Leadership can be defined in two words: "Follow Me"

manbearpig's picture

sayandarula: manbearpig: Le

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 2:02pm

-MBP

manbearpig's picture

illiniPride: Dimethyltrypta

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 2:03pm

-MBP

Dimethyltryptamine's picture

the example itself isn't

(Baboon, 110
 
Points)
 on 5/7/12 at 2:04pm
prospie's picture

Mondays are miserable enough

(King Kong, 1,680
 
Points)
 on 5/7/12 at 2:05pm

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HFFBALLfan123's picture

manbearpig: sayandarula:

PE
(King Kong, 1,371
 
Points)
 on 5/7/12 at 2:07pm
illiniPride's picture

manbearpig: Lol thanks dude.

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 2:09pm

Leadership can be defined in two words: "Follow Me"

illiniPride's picture

prospie: Mondays are

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 2:18pm

Leadership can be defined in two words: "Follow Me"

manbearpig's picture

HFFBALLfan123: manbearpig:

CO
(Neanderthal, 3,029
 
Points)
 on 5/7/12 at 2:22pm

-MBP

MrJetSet's picture

Idk if this has been said

CO
(Orangutan, 252
 
Points)
 on 5/7/12 at 2:25pm
illiniPride's picture

Dimethyltryptamine: the

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 2:26pm

Leadership can be defined in two words: "Follow Me"

aempirei's picture

illiniPride: prospie: Monda

IB
(Gorilla, 726
 
Points)
 on 5/7/12 at 2:40pm

My name is Nicky, but you can call me Dre.

aempirei's picture

I would say 120 panthers

IB
(Gorilla, 726
 
Points)
 on 5/7/12 at 2:43pm

My name is Nicky, but you can call me Dre.

mrbeancounter's picture

Panthers are hunters and will

(Monkey, 33
 
Points)
 on 5/7/12 at 2:52pm
Buddyfox's picture

aempirei: illiniPride: pr

O
 
Points)
 on 5/7/12 at 3:07pm

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MrJetSet's picture

I would like to know why my

CO
(Orangutan, 252
 
Points)
 on 5/7/12 at 3:32pm
Buddyfox's picture

MrJetSet: I would like to

O
 
Points)
 on 5/7/12 at 3:39pm

See my Monday Morning Brainteasers

illiniPride's picture

MrJetSet: I would like to

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 3:42pm

Leadership can be defined in two words: "Follow Me"

mrbeancounter's picture

The question is how smart and

(Monkey, 33
 
Points)
 on 5/7/12 at 3:50pm
bigun's picture

manbearpig: Let's do this by

(Monkey, 61
 
Points)
 on 5/7/12 at 3:52pm
illiniPride's picture

bigun: manbearpig: Let's do

IB
(King Kong, 1,099
 
Points)
 on 5/7/12 at 4:08pm

Leadership can be defined in two words: "Follow Me"

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