If 12 people are to be divided into 3 committees of respective sizes 3, 4, and 5, how many divisions are possible?

1320

Step-by-step explanation:

I think this is a permutation problem

n p r = n! / (n-r)!

12 P 3 = 12! / (12-3)!

= 12! / 9!

= 12× 11 ×10 × 9! / 9!

The 9! in the numerator and denminator will cancel out

12 P 3 = 12 × 11 × 10 = 1320