A steamer goes downstream from one port to another in 9 hours. It covers the same distance upstream in 10 hours. If the speed of the stream be 1 km/h, find the speed of the steamer in still water and the distance between the ports.
Let the speed of the steamer in still water be x km/h
Speed in downstream = x + 1, Speed in upstream = x - 1
Distance = speed × time
According to the question
9(x + 1) = 10(x - 1)
By cross multiplication
⇒ 9x + 9 = 10x - 10
⇒ x = 19 km/h
Distance between the ports = 9(19 + 1) = 180 km