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#1 2011-12-27 03:35:33

juantheron
Member
Registered: 2011-10-19
Posts: 312

no. of ways

In How Many Different Ways Can 12 Different Fruits Be Given Away To 3 Boys,

So That Each Boy Gets At Least One Fruit?

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#2 2011-12-27 07:22:44

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: no. of ways

Hi juan;


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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#3 2011-12-28 04:21:59

juantheron
Member
Registered: 2011-10-19
Posts: 312

Re: no. of ways

yes bobbym thanks

but how can you get it

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#4 2011-12-28 09:55:13

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

Re: no. of ways

Hi juan;

This is "a distinguishable balls into distinguishable urns problem."

There are two ways that I can think of.

1) A formula:

Where n is the number of distinguishable balls, k is the number of distinguishable boxes, r is the number of occupied boxes.

2) A generating function:

We are concerned with the coefficient of x^12, which we multiply by 12!.


In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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