Question

A car travels a certain distance with a speed of 50 km/h ,and returns with a speed of 40 km/h. calculate the average speed for the whole journey

Answer 1

Take whole distance to be x km and calculate time by ,

S=D/T

50=x/t

Therefore ,

t =x/50

and by using this you can calculate time when the car travels with 30 km/hr.