Question

A car moves through 20km at a speed of 40km/h ,and the next 20km at a speed of 60km/h . Calculate its average speed.​

Answer 1

For first 20 km, time taken by car is

t1 = 20/40

t1 = 1/2

For next 20 km, the time taken by car is

t2 = 20/60

t2 = 1/3

Avg. speed = total distance/total time

Avg. speed = 40/1/2+1/3

Avg. speed = 40×6/5

Avg. speed = 48 km/ h