There are 30 students in Mr. McRoberts' Grade 8 class. One-third of the students are girls. Three-quarters of the boys play basketball. The number of boys in the class who play basketball is
(A) 3
(B) 22
(C) 10
(D) 20
(E) 15
Since one-third of the 30 students in the class are girls, then 10 of the students are girls. This means that 20 of the students are boys. Three-quarters of the 20 boys play basketball, which means that 15 of the boys play basketball.