Question

A motorcyclist drives from place A to B with a uniform speed of 30 km $h^{-1}$ and returns from place B to A with a uniform speed of 20 km $h^{-1}$. Find his average speed.

Answer 1

Let distance between A and B is D
Then, time taken by motorcyclist with uniform speed 30 km/h

T₁ = = hrs

Again, they return with uniform speed 20 km , so time taken by motorcyclist , T₂ =

Now,

average speed of motorcyclist =


= km/h





= 24 km/h