The speed of a boat along the stream is 8 km/h and against the stream is 6 km/hr. The time taken by the boat to sail 28 km in still water is
2 hrs
3 hrs
4 hrs
8 hrs
Explanation:
Given, Speed downstream = 8 km/h Speed upstream = 6 km/h
∴ Speed of boat in still water= speed downstream +speed upstream /2.
=$\dfrac{8+6}{2}$
=$\dfrac{14}{2}$
=7 km/hr
Required time =Distance/speed of boat = 28/7 =4hrs.
Given, Speed downstream = 8 km/h Speed upstream = 6 km/h
∴ Speed of boat in still water= speed downstream +speed upstream /2.
=$\dfrac{8+6}{2}$
=$\dfrac{14}{2}$
=7 km/hr
Required time =Distance/speed of boat = 28/7 =4hrs.