A firm has 4 senior partners and 5 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. (2 groups are considered different if at least one group member is different) Select:
A) 66 B) 74 C) 82 D) 90 E) 98
The total number of ways to form a group of 3 is 9C3 = 84   The number of groups without a senior partner is 5C3 = 10   The number of groups which include a senior partner is  84-10= 
<gadget id="calculator"> 84-10</gadget>
<output>74</output>
74   The answer is 74.
<result>B</result>
A firm has 4 senior partners and 5 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. (2 groups are considered different if at least one group member is different)