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Benny
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What a rhino looks like
« on: Jun 15th, 2009, 7:00pm » |
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Presume that you do not know what a rhino looks like. Now the question goes like this: If one day while walking in a forest with two of your close friends, one friend shows you an elephant and tells that this is a rhino, and another friend shows you a hippopotamus and tells you that this is a rhino, who would you believe?
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Ronno
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Re: What a rhino looks like
« Reply #1 on: Jun 15th, 2009, 8:34pm » |
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If I don't know how one of elephant or hippopotamus looks like, then I will believe that option. If I know how both look like, I will believe neither of them. If I don't know how either looks like, I will believe the friend who lies less.
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towr
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Re: What a rhino looks like
« Reply #2 on: Jun 16th, 2009, 12:30am » |
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Do I know any greek?
rhino= nose, ceros [keras] = horn
Neither elephant nor hippopotamus have a horn on their nose.
Oh, wait, he only says "this is a rhino"? Well, then obviously it's the elephant, on account of the nose. Assuming I don't know what an elephant is beforehand either.
And I'd double check on wikipedia after I got home.
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| « Last Edit: Jun 16th, 2009, 12:32am by towr » |
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Grimbal
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Re: What a rhino looks like
« Reply #3 on: Jun 16th, 2009, 8:24am » |
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on Jun 15th, 2009, 7:00pm, BenVitale wrote:| Presume that you do not know what a rhino looks like. Now the question goes like this: If one day while walking in a forest with two of your close friends, one friend shows you an elephant and tells that this is a rhino, and another friend shows you a hippopotamus and tells you that this is a rhino, who would you believe? |
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Both.
I would believe the word rhino is a generic term for all large animals.
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Benny
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Re: What a rhino looks like
« Reply #4 on: Jun 16th, 2009, 9:10am » |
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Actually, you shouldn't believe either of them.
Why?
I asked you to "Presume that you do not know what a rhino looks like, not that you are unaware of what a hippo and elephant look like
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towr
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Re: What a rhino looks like
« Reply #5 on: Jun 16th, 2009, 9:19am » |
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on Jun 16th, 2009, 9:10am, BenVitale wrote:| I asked you to "Presume that you do not know what a rhino looks like, not that you are unaware of what a hippo and elephant look like |
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So, suppose you don't know what an arachnid is. I hold up a spider and tell you that that is, in fact, an arachnid. Should you disbelieve that merely because you know what a spider is?
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Benny
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Re: What a rhino looks like
« Reply #6 on: Jun 16th, 2009, 9:41am » |
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You have changed, complicated the problem.
Arachnids are a class, a set of elements of which a spider is an element.
Arachnids (A) : {spider, ticks, termites, scorpions, ...}
In the original problem, the 3 animals in question belong to the same class.
rhino ............... you do not know
Elephant ......... you know
Hippo .............. you know
No, wait, we're not sure whether the Rhino belongs to the same class (o set of elements)
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towr
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Re: What a rhino looks like
« Reply #7 on: Jun 16th, 2009, 10:11am » |
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Even if you know they are the same "class", it doesn't remove the problem that the same type of animal can have multiple names.
Donkeys and asses; cockerels and roosters; Loxodonta africana and african bush elephant. (It gets real easy once you include latin names; but as the first two example show, that's not even necessary in some cases).
The issue is that you don't know whether "rhino" is an alternative name, or a superclass, or subclass.
on Jun 16th, 2009, 9:41am, BenVitale wrote:| Arachnids (A) : {spider, ticks, termites, scorpions, ...} |
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Termites are definitely insects, not arachnids.
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| « Last Edit: Jun 16th, 2009, 10:12am by towr » |
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Benny
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Re: What a rhino looks like
« Reply #8 on: Jun 16th, 2009, 10:37am » |
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The problem asks, "Who would you believe?"
I think you can only answer: neither.
Because you know what elephant looks like, and you know what a hippo looks like.
And, to simplify the problem, we need to assume that "Rhino" is not another name for "Elephant" or "Hippo." We are not dealing with multiple names.
We need to make an assumption in order to solve the problem.
Do you see another approach?
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Hippo
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Re: What a rhino looks like
« Reply #9 on: Jun 16th, 2009, 11:57am » |
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I don't think I am Rhino so I would rather believe the Elephant is.
Is it correct answer? 
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towr
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Re: What a rhino looks like
« Reply #10 on: Jun 16th, 2009, 12:04pm » |
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on Jun 16th, 2009, 10:37am, BenVitale wrote:| The problem asks, "Who would you believe?" |
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Indeed it does; it does not ask "who would BenVitale believe?", or "who should you believe?" It asks the reader who (s)he would believe; and whatever the reader truthfully answers is therefore correct.
And even in the latter case, it's open to debate who you should believe, because it depends on circumstances that weren't specified.
Quote:| I think you can only answer: neither. |
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That contradicts the fact I answered differently 
Quote:| Do you see another approach? |
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Several; for starters there's all the different answers mentioned in this thread. I don't see why the problem should just have one answer; it is much more interesting to see in what different ways people can think about it.
And really, how close are these friends if you can't even trust them?
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Benny
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Re: What a rhino looks like
« Reply #11 on: Jun 16th, 2009, 2:41pm » |
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These friends are close, and you can trust them ... they are also gamers, they are big fans of Game theory.
You're right, I shouldn't limit myself to a unique solution.
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chronodekar
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Re: What a rhino looks like
« Reply #12 on: Jun 25th, 2009, 4:22am » |
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Something scary: 
What if the friends introduced one as a male and the other as the female? Considering that you don't know all 3, ... frightening!!
-chronodekar
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