Calculate how long it will take a swimmer to swim a distance of 10km against the current of a river which flows at 3km/hr, given that he can swim in still water at 5km/h
Pick:
A) 3	B) 4	C) 5	D) 6	E) 7

Rationale: "swim in still water at = 5 speed of river = 3 us = 5 - 3 = 2 distance = 10 t = 10 / 2 = 5 answer : c"
Answer: C