A law firm has six senior and fourteen junior partners. A committee of 3 partners is selected at random to represent the firm at a conference. What is the probability that at least one of the junior partners is on the committee?

Answer 1

number of possible committees
= C(20,3) = 1140

number with NO junior partners = C(6,3) = 20
so the number with at least one junior = 1140-20 = 1120

prob of at least one junior = 1120/1140
= 56/57 = appr .98