The local skating rink pays Mary a fixed rate per pupil plus a base amount to work as a skating instructor. She earns $90 for instructing 15 students on Monday afternoon. Last Friday, she earned $62 for working with 8 students. Lisa is also a skating instructor. She receives half the base amount that Mary does, but she is paid twice as much per student. Who would earn more money instructing a class of 20 students? A.) Lisa would earn $120 more than Mary.
B.) Lisa would earn $65 more than Mary.
C.) Mary would earn $15 more than Lisa.
D.) Mary would earn $10 more than Lisa.