Question

A car covers four successive three km stretches at speeds of 10 km/hr,20 km/hr 30 km/hr and 60 km/hr respectively. Its average speed over this distance :

Answer 1

avg speed = 20kmperhr

Answer 2

Answer:

20 Km/hr

Explanation:

4 successive 3 km=4*3=12 km in total

Given :

time=distance/speed

so,

3/10 + 3/20 + 3/30 +3/60

->(18+9+6+3)/60

->36/60

->3/5

to find average speed,

speed=distance/time

=>speed=12/(3/5)

speed=12*5/3=4*5=20 km/hr