Question

A bus covers 3 equal distances. The first is covered with speed 10 km/hr second with speed 20 km/hr and third with 60 km/hr , then find its average speed in km/hr .​

Answer 1

since the distances are equal

so total distance=3d

1. time taken to cover the distance with 10km/h speed=d/10

2. with 20km/h=d/20

3. with 60km/h=d/60

average speed=total distance/total time

s=3d/(d/10+d/20+d/60)

s=18km/h