Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Topic: how many ways to pick two teams of 10 out of a group of 20 people
Replies: 12   Last Post: Feb 5, 2013 2:20 PM

 Messages: [ Previous | Next ]
 David Bernier Posts: 3,662 Registered: 12/13/04
Re: how many ways to pick two teams of 10 out of a group of 20 people
Posted: Feb 5, 2013 8:04 AM

On 02/05/2013 02:45 AM, G Patel wrote:
> Is it 20 choose 10 or do I have to divide by 2?
>
>
>

Team A: C(20, 10)
Team B: 1: 10 left.

C(20, 10) ways to chose the ordered pair (Team A, Team B).

If the teams are unordered, just two complemetary subsets,
{X, Y} with |X|=|Y|=10, C(20,10)/2 ways of constructing
{X, Y} .

David Bernier

--
dracut:/# lvm vgcfgrestore
File descriptor 9 (/.console_lock) leaked on lvm invocation. Parent PID
993: sh
Please specify a *single* volume group to restore.

Date Subject Author
2/5/13 gaya.patel@gmail.com
2/5/13 William Elliot
2/5/13
2/5/13 fom
2/5/13 quasi
2/5/13 fom
2/5/13 Frederick Williams
2/5/13 fom
2/5/13 Virgil
2/5/13 quasi
2/5/13 David Bernier
2/5/13 Scott Berg
2/5/13 Ray Koopman