Solve the question of and select the option from the choices A through D/E. Check your Answer and view the explanation.
The distance between two stations A and B is 778 km. A train covers the journey from A to B at 84 km per hour and returns back to A with a uniform speed of 56 km per hour. Find the average speed of train during the whole journey.
=(2×84×56/84+56)
=(2×84×56/140)
=67.2 km/hr