Question

car drives from a to b at a uniform speed 30 kilometres per hour and returns back with a speed of 20 km per hour find its average speed​

Answer 1

Answer:

Explanation:

let distance between A and B be D

time taken by car be T1=D/30 hrs

time taken by car for returning T2=D/20hrs

so,average speed of car = total distance/time taken

(D + D )/(D/30 + D/20) km/h

2 × 30 × 20/(30 + 20) km/h

24 km/h