300
40 students.
15 = (S - 1/4S) x 1/2
15 = 3/4S x 1/2
15 = 3/8S
15 x 8 = 3/8S x 8
120 = 3S
S = 40
At the beginning of a class, one-fourth of the students leave to attend band practice. Later, one half of the remaining students leave to go to PE. If there were 15 students remaining in the class at the end, how many students were in class at the beginning?