Problema Solution

A motorboat can travel 4 km upstream in the same time it can travel 9 km downstream. If the velocity of the current is 8 kph, find the velocity of the boat in still water.

Answer provided by our tutors

let speed in still water = x kph

4/(x-8) = 9/(x+8)

=> 4x + 32 = 9x - 72

=> 5x = 104

=> x = 20.8 kph