Calculate how long it will take a swimmer to swim a distance of 3km against the current of a river which flows at 1.7km/hr, given that he can swim in still water at 3km/h  Answers.
A) 2.31	B) 9.31	C) 1.31	D) 4.31	E) 3.31

Rationale: "swim in still water at = 3 speed of river = 1.7 us = 3 - 1.7 = 1.3 distance = 3 t = 3 / 1.3 = 2.31 answer : a"
Answer: A