Re: Computing nCr how?
- To: mathgroup at smc.vnet.net
- Subject: [mg94838] Re: [mg94820] Computing nCr how?
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Mon, 29 Dec 2008 06:33:26 -0500 (EST)
- Organization: Mathematics & Statistics, Univ. of Mass./Amherst
- References: <200812271203.HAA12436@smc.vnet.net>
- Reply-to: murray at math.umass.edu
An unfortunate, but standard mathematical term -- "combinations". You
mean the number of r-element subsets of an n-element set. This is the
binomial coefficient often denoted
n
( )
r
(with a large pair of parentheses).
This is the same, of course, as the coefficient of x^r in the expansion
of the binomial power (1+x)^n. In Mathematica, this binomial
coefficient is:
Binomial[n,r]
Affan wrote:
> Hi,
> I know this sounds simple but I cant find the function in mathematica
> to compute nCr (i.e. number of combination for n obj chosen in groups
> of r). Can anyone help?
>
> Thanks
>
>
--
Murray Eisenberg murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower phone 413 549-1020 (H)
University of Massachusetts 413 545-2859 (W)
710 North Pleasant Street fax 413 545-1801
Amherst, MA 01003-9305