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.
Answer & explanation
Correct answer: option 3
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