A man travels 50 km at speed 25 km/hr and next 40 km at 20 km/hr and there after travel 90 km at 15 km/hr. His average speed is :

A. 18 km/hr

B. 25 km/hr

C. 20 km/hr

D. 15 km/hr

Answer: Option A

Solution(By Examveda Team)

$$\eqalign{ & {\text{Average speed }} = \frac{{{\text{Total distance }}}}{{{\text{Total time}}}} \cr & {\text{Average speed}} = \frac{{50 + 40 + 90}}{{2 + 2 + 6}} \cr & {\text{Average speed}} = \frac{{180}}{{10}} \cr & {\text{Average speed}} = 18{\text{ km/hr}} \cr} $$