Answer:
Given,
Distance traveled = 20 km
Speed = 60 km/h
So, timetaken=DistanceSpeed=2060=13h
For the next journey
Distance traveled = 20 km
Speed = 80 km/h
So, timetaken=DistanceSpeed=2080=14h
Now,
Total distance traveled = 20 + 20 = 40 km
Total time taken = 13+14=712
We know,
Averagespeed=TotaldistancetraveledTotaltimetaken=40712=68.5 km/h
Hence the average speed of the train is 68.5 km/h
