# combinatorics I guess!

• November 22nd 2006, 12:22 PM
justin
combinatorics I guess!
okay umm.. I am new at this website and I need help in math!
I was wondering if you guys cantell me if I am doing my work right?

here it is:

express each of the following as a product:

a.6!

my work:
720

6!=6x5x4x3x2x1

or on my calculator:
6 math-->prb-->4--> enter= 720

b. 7C 2

how would i do this one? thanks for your help in advance!:cool:
• November 22nd 2006, 12:46 PM
ThePerfectHacker
Quote:

Originally Posted by justin
okay umm.. I am new at this website and I need help in math!
I was wondering if you guys cantell me if I am doing my work right?

here it is:

express each of the following as a product:

a.6!

my work:
720

6!=6x5x4x3x2x1

or on my calculator:
6 math-->prb-->4--> enter= 720

b. 7C 2

how would i do this one? thanks for your help in advance!:cool:

The first one is correct.
The second one is,
$\frac{7!}{2!(7-2)!}$