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 :

Solution (By Examveda Team)

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