Question

A certain law firm consists of 4 senior partners and 6 junior partners. How many different groups of 3 partners can be formed in which at least one member of the group is a senior partner? (two groups are considered different if at least one group member is different.)

Answer 1

Answer:

100

Step-by-step explanation:

Total # of different groups of 3 out of 10 people: C310=120C103=120;

# of groups with only junior partners (so with zero senior memeber): C36=20C63=20;

So the # of groups with at least one senior partner is {all} - {none} = {at least one} = 120 - 20 = 100.

Answer: 100