Question

A car moves at 80 km/hr in the first half of total time of motion and at 40 km/h–1 in the later half. Its average speed is

Answer 1

Let t be the total time.
Distance covered at 80km/hr = 80*t/2
= 40t km

Distance covered at 40km/hr = 40*t/2
= 20t kn

Now,
Average speed = Total Distance/Total time
= (40t + 20t)/t
= 60km/hr ans

Answer 2

hello friends
try the formula,
and check the answer