Question

A bus travels a distance of 120 km with a speed of 40 km/h and returns with a speed of 30 km/h. Calculate the average speed for the entire journey.

Answer 1

Average speed = Total distance travelled / Total time taken

Total Distance Travelled = 120+120 = 240 km

Time taken for going = Distance/ Speed = 120/40 = 3 hrs

Time taken for return = Distance/ Speed  = 120/30 = 4hrs

Thus, total time taken = 3+4 = 7 hrs

Average speed = 240 / 7 = 34.3 km/h

Answer 2

the average speed is defined properly by time.

but the average is about 35 km/h