Question

from a group of 14 junior and 9 senior students, determine how many committees of 8 students can be chosen if all chosen students are junior students?

Answer 1

so take the seniors out of the problem

how many groups of 8 from 14 ?

combinations:

C(n,r) = n!/[ r!*(n-r)!]

C(14,8) = 14!/ [8! *6!]

= 14*13*12*11*10*9/(6*5*4*3*2)

= 7*13*11*3 = 3003