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#1 2008-10-01 13:08:12

saveme
Guest

combinatorial proof

Hi big_smile

I'm really really having hard time proving this in a combinatorial way:

the problem is that I do not even understand what DOES IT COUNT sad

can you help me sorting this out?

#2 2008-10-01 13:09:10

saveme
Guest

Re: combinatorial proof

EDIT: that '(nk)' is actually 'n choose k' but I didn't know how to do it in LaTex

#3 2008-10-01 17:56:24

Ricky
Moderator
Registered: 2005-12-04
Posts: 3,791

Re: combinatorial proof

1 = 1
1 + 2  = 3
1 + 2 + 3 = 6
1 + 2 + 3 + 4 = 10


"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

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#4 2008-10-02 00:56:03

saveme
Guest

Re: combinatorial proof

I do not think that is the correct answer: the right side of the equality does not count the sum of the first n integers wink

anyway I solved this one tonight, so this can be closed

#5 2008-10-02 10:25:41

Ricky
Moderator
Registered: 2005-12-04
Posts: 3,791

Re: combinatorial proof

Ah, I did not see the factorial there.


"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

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#6 2008-10-04 09:42:55

G_Einstein
Member
Registered: 2008-08-30
Posts: 124

Re: combinatorial proof


Se Zoti vete e tha me goje,se kombet shuhen permbi dhe,por SHqiperia do te roje,per te,per te luftojme ne.
God said that all nation exincts on the ground,but Albania will survive,for it,for it we are fighting.

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#7 2008-10-04 09:47:43

G_Einstein
Member
Registered: 2008-08-30
Posts: 124

Re: combinatorial proof


Se Zoti vete e tha me goje,se kombet shuhen permbi dhe,por SHqiperia do te roje,per te,per te luftojme ne.
God said that all nation exincts on the ground,but Albania will survive,for it,for it we are fighting.

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#8 2008-10-04 09:48:21

G_Einstein
Member
Registered: 2008-08-30
Posts: 124

Re: combinatorial proof

Last edited by G_Einstein (2008-10-04 10:03:54)


Se Zoti vete e tha me goje,se kombet shuhen permbi dhe,por SHqiperia do te roje,per te,per te luftojme ne.
God said that all nation exincts on the ground,but Albania will survive,for it,for it we are fighting.

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#9 2008-10-04 09:54:50

G_Einstein
Member
Registered: 2008-08-30
Posts: 124

Re: combinatorial proof

Last edited by G_Einstein (2008-10-04 10:02:40)


Se Zoti vete e tha me goje,se kombet shuhen permbi dhe,por SHqiperia do te roje,per te,per te luftojme ne.
God said that all nation exincts on the ground,but Albania will survive,for it,for it we are fighting.

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#10 2008-10-04 10:04:58

G_Einstein
Member
Registered: 2008-08-30
Posts: 124

Re: combinatorial proof

Last edited by G_Einstein (2008-10-04 10:08:57)


Se Zoti vete e tha me goje,se kombet shuhen permbi dhe,por SHqiperia do te roje,per te,per te luftojme ne.
God said that all nation exincts on the ground,but Albania will survive,for it,for it we are fighting.

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#11 2008-10-04 10:09:30

G_Einstein
Member
Registered: 2008-08-30
Posts: 124

Re: combinatorial proof

Sorry,I'm trying to write you the answer but it doesn't work


Se Zoti vete e tha me goje,se kombet shuhen permbi dhe,por SHqiperia do te roje,per te,per te luftojme ne.
God said that all nation exincts on the ground,but Albania will survive,for it,for it we are fighting.

Offline

#12 2008-10-04 12:12:00

Ricky
Moderator
Registered: 2005-12-04
Posts: 3,791

Re: combinatorial proof

Fixed your LaTeX, G_Einstein.  But saveme already said:

anyway I solved this one tonight, so this can be closed


"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

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