A person can swim in still water at 8 km/h. If the speed of water 4 km/h, how many hours will the man take to swim back against the current for 8km? Choose one
A) 2	B) 4	C) 5	D) 6	E) 7

Rationale: "m = 8 s = 4 us = 8 - 4 = 4 d = 4 t = 8 / 4 = 2 answer : a"
Answer: A