A can run 4 times as fast as B and gives B a start of 72 m. How long should the race course be so that A and B might reach in the same time? Choose the correct choice.
A) 70 m
B) 60 m
C) 80 m
D) 65 m
E) 96 m

Rationale: "speed of a : speed of b = 4 : 1 means in a race of 4 m a gains 3 m . then in a race of 72 m he gains 72 * ( 4 / 3 ) i . e 96 m answer : e"
Answer: E