A person can swim in still water at 4 km/h. If the speed of water 2 km/h, how many hours will the man take to swim back against the current for 14km?  Choose the correct answer.
A) 3
B) 6
C) 8
D) 9
E) 7

Rationale: m = 4 s = 2 us = 4 - 2 = 2 d = 14 t = 14 / 2 = 7 answer : e
Answer: E