Question

A car travels at a speed of 80 km/h during the first half of its running time and at 40km/h during the other half. Find the average speed of the car. (60km/h) ​

Answer 1

Explanation:

the answer is in the above picture

Answer 2

For first half, distance=v1t/2.........for second half, distance=v2t/2

Average speed=v1t/2+v2t/2 the whole divided by t/2+t/2

                   =v1t+v2t/2/t

                   =v1+v2/2

 

                     80+40/2 = 60 km/h