Answer :
Given:
The number of male professors = 15.
The number of female professors = 9.
The number of male teaching assistants = 6.
The number of female teaching assistants = 12.
A person is selected randomly from the group.
Required:
We need to find the probability that the selected person is a professor or a male.
Explanation:
The total number of people in the group = 15+9+6+12 = 42
n(S) =The total number of people in the group
[tex]n(S)=42[/tex]Let A be the event that the selected person is a professor or a male.
The number of people who are professors or male = 15+9+6 = 30
n(A)= The number of people who are professors or male.
[tex]n(A)=30[/tex]Let P(A) be the probability that the selected person is a professor or a male.
[tex]P(A)=\frac{n(A)}{n(S)}[/tex][tex]P(A)=\frac{30}{42}[/tex][tex]P(A)=\frac{15}{21}=\frac{5}{7}[/tex]Final answer:
The probability that the selected person is a professor or a male is 5/7.