While on vacation, Enzo sleeps 115% as long as he does while school is in session. He sleeps an average of S hours per day while he is on vacation. Which of the following expressions could represent how many hours per day Enzo sleeps on average while school is in session?
A.1.15S
B.S/1.15
C.100/115S
D.17/20S
E.(1.15-0.15)S