Question

A boat's speed in still water is 5 km/hr. While river is flowing with a speed of 2. km/hr and time taken to cover a certain distance upstream is 2h more than time taken to cover the same distance downstream. Find the distance ? 1) 7 km 2) 10.5 km 3) 21 km 4) 14 km 5) 12 km​

Answer 1

Answer:

Let the distance be x km.

Speed downstream = (5 + 2) = 7 km/h

and speed upstream = (5 - 2) = 3 km/h

According to the question,

x3−x7=2=7x−3x=21×2

Therefore, x=21×24 = 10.5 km/h