Question

A car has to cover the distance 60km,if half of the total time it travels with velocity 80km/H and in rest half time it's speed becomes 40km/H,Then what is the average speed of the car?

Answer 1

The problem can be solved by two methods
Method 1 :
Vav = 80 + 40 / 2
= 120/2
= 60 km /h
Method 2 :
Let the half time intervals be t
Therefore 60 = 80t + 40t
t=1/2
total time = 1/2*2 = 1hr
vav = Total distance / Total time
= 60 / 1
= 60 km/h