A steamer goes downstream from one port to another in 4 h. It covers the same distance upstream in 5 h. If the speed of the stream is 2 km/h, then find the distance between the two ports.?
Correct Answer: 80 km
Explanation:
Let the distance between the two ports be x km.
Then, speed downstream = x/4
And speed upstream = x/5
∴ Speed of the stream = [speed downstream + speed upstream] / 2 = (x/4 - x/5)/2
⇒ (5x -4x)/40 = 2
⇒ x/40 = 2
∴ x = 80 km
