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        riddles >> easy >> What a rhino looks like
        
(Message started by: BenVitale on Jun 15^th, 2009, 7:00pm)

Title: What a rhino looks like
Post by BenVitale on Jun 15^th, 2009, 7:00pm

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?

Title: Re: What a rhino looks like
Post by Ronno on Jun 15^th, 2009, 8:34pm

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.

Title: Re: What a rhino looks like
Post by towr on Jun 16^th, 2009, 12:30am

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.

Title: Re: What a rhino looks like
Post by Grimbal on Jun 16^th, 2009, 8:24am

on 06/15/09 at 19:00:06, BenVitale wrote:

Both.
I would believe the word rhino is a generic term for all large animals.

Title: Re: What a rhino looks like
Post by BenVitale on Jun 16^th, 2009, 9:10am

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

Title: Re: What a rhino looks like
Post by towr on Jun 16^th, 2009, 9:19am

on 06/16/09 at 09:10:00, 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

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?

Title: Re: What a rhino looks like
Post by BenVitale on Jun 16^th, 2009, 9:41am

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)

Title: Re: What a rhino looks like
Post by towr on Jun 16^th, 2009, 10:11am

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 06/16/09 at 09:41:48, BenVitale wrote:

Arachnids (A) : {spider, ticks, termites, scorpions, ...}

Termites are definitely insects, not arachnids.

Title: Re: What a rhino looks like
Post by BenVitale on Jun 16^th, 2009, 10:37am

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?

Title: Re: What a rhino looks like
Post by Hippo on Jun 16^th, 2009, 11:57am

I don't think I am Rhino so I would rather believe the Elephant is.

Is it correct answer? :D

Title: Re: What a rhino looks like
Post by towr on Jun 16^th, 2009, 12:04pm

on 06/16/09 at 10:37:31, BenVitale wrote:

The problem asks, "Who would you believe?"

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.

That contradicts the fact I answered differently ;)

Quote:

Do you see another approach?

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?

Title: Re: What a rhino looks like
Post by BenVitale on Jun 16^th, 2009, 2:41pm

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.

Title: Re: What a rhino looks like
Post by chronodekar on Jun 25^th, 2009, 4:22am

Something scary: :o

[hide]What if the friends introduced one as a male and the other as the female? Considering that you don't know all 3, ... frightening!![/hide]

;)

-chronodekar