A boatman can row 96 km downstream in 8 hr. If the speed of the current is 4 km/hr, then find in what time will be able to cover 8 km upstream? Pick
A) 6 hr  B) 2 hr  C) 4 hr  D) 1 hr  E) none of these

Rationale: "explanation : speed downstream = 96 ⁄ 8 = 12 kmph speed of current = 4 km / hr speed of the boatman in still water = 12 - 4 = 8 kmph speed upstream = 8 - 4 = 4 kmph time taken to cover 8 km upstream = 8 ⁄ 4 = 2 hours . answer : option b"
Answer: B