Question

A car travels first 30 km at a uniform speed of 20 km

/hr and went 30 km at a uniform speed of 40 km/hr
Find its average speed in km/hr

Answer 1

20 = 30 / t1

t1 = 3/2

40 = 30 / t2

t2 = 3/4

average speed = total distance / total time taken

= 30 + 30 / 3/2 + 3/4

= 60 /9/4

= 60 × 4/9

= 26.667