A man goes from Mysore to Bangalore at a uniform speed of 40 km/hr and comes back to Mysore at a uniform speed of 60 km/hr. His average speed for the whole journey is :

A. 48 km/hr

B. 50 km/hr

C. 54 km/hr

D. 5 km/hr

Answer: Option A

Solution(By Examveda Team)

$$\eqalign{ & {\text{Average speed}} \cr & = \frac{{{\text{2xy }}}}{{x + y}} \cr & = \frac{{2 \times 40 \times 60}}{{40 + 60}} \cr & \therefore {\text{Average speed}} = {\text{4}}8{\text{ km/hr}} \cr} $$