There are 25 students in a class in which 15 boys and 10 girls. The class teacher select either a boy or girl for monitor of the class. In how many ways the class teacher can make this selection?

Explanation

Since, there are 15 ways to select a boy, so there are 10 ways to select a girl. Hence, by the fundamental principal of addiition, either a boy or a girl can be performed in 15+10=25 ways.