you have 12 team members but can only use 9 on a team. How many different teams can you make

Question

you have 12 team members but can only use 9 on a team. How many different teams can you make

Answer 1

Hi Lucille,

 

This is finding possible number of samples of 9 out of 12. We need to use combination.

C(12,9) = 12! / ((12-9)!*9!)

= 12*11*10*9! / 9!*(3*2*1)

= 220

Answer 2

12 choose 9

 

12C9 = 12!/(9!)(12-9)! = (12·11·10)/(3·2) = 220