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 ?
"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"
divide(8, subtract(subtract(divide(96, 8), 4), 4))