Question

A motorcyclist drives from A to B with a uniform speed of 30 km h–¹ and returns back with a speed of 20 km h^–1. Find its average speed

Answer 1

Let AB = x, So t 1=x /30, and t2 =  x /20 

Total time = t1 + t2 = 5x / 60  h.   

Average speed for entire journeyTotal distance /Total Time  = 2x / 5x / 60= 24 km h^-1