A boat can travel in still water at 7 km/h and the speed of the stream is 3 km/h. Find the total tin1e (in hours) taken by the boat to travel 60 km upstream and return to the starting point.

21

We know that,

Distance = Speed × Time

Given,

A boat can travel in still water = 7 km/h

The speed of the stream = 3 km/h.

Upstream speed = 7 - 3 = 4 km/h

Downstream speed = 7 + 3 = 10 km/h

Now, the total time taken by the boat to travel 60 km upstream and return to the starting point

= \(\frac{60}{4}\) + \(\frac{60}{10}\) = 21 hours