Question

On a 80 km track ,a train travels 40 km with uniform speed of 30 km/h.How fast must the train travel next 40 km so as to have average speed 40 km/h for the entire trip.

Answer 1

Answer:

google it it is too easy

Answer 2

Average speed = Total distance / Total time

40 = 80 / (t1 + t2)

t1 + t2 = 2

40/30 + 40/v = 2 ……[∵ Time = Distance/Speed]

40/v = 2 - 4/3

40/v = 2/3

v = 60 kmph

Train should travel at the rate of 60 kmph for next 40 km