A certain team consists of 5 professors and 4 teaching assistants. How many different teams of 3 can be formed in which at least one member of the group is a professor? (Two groups are considered different if at least one group member is different.)
Choose the correct choice from the following: A) 74 B) 80 C) 86 D) 92 E) 98
The total number of ways to form a group of 3 from 9 people is 9C3 = 84   The number of ways to form a group without a professor is 4C3 = 4   The total number of ways to form a valid group is   84 - 4= 
<gadget id="calculator">  84 - 4</gadget>
<output>80</output>
80.   The answer is 80.
<result>B</result>
A certain team consists of 5 professors and 4 teaching assistants. How many different teams of 3 can be formed in which at least one member of the group is a professor? (Two groups are considered different if at least one group member is different.)