Question

A steamer goes downstream from one point to another in 9 hours. It covers the same distance upstream in 10 hours. If the speed of the stream be 1 km/hr, find the speed of the steamer in still water and the distance between the ports.

Answer 1

It is given that the speed of the stream is 1 km/h . 
Let the speed of the steamer in still water be x km/h . 
∴ Downstream speed = (x + 1) km/h
Upstream speed = (x - 1) km/h
The downstream and upstream distances are same; therefore, we have: 
9(x + 1) = 10(x - 1)
or 9x + 9 = 10x - 10
or x = 19
∴ Speed of the steamer in still water = 19 km/h . 
Distance between the ports = 9(19 + 1) = 180 km .