A man covers a total distance of 100 km on bicycle. For the first 2 hours, the speed was 20 km/hr and for the rest of the journey, it came down to 10 km/hr. The average speed will be :

A. $$12\frac{1}{2}$$ km/hr

B. 13 km/hr

C. $$\frac{1}{8}$$ km/hr

D. 20 km/hr

Answer: Option A

Solution(By Examveda Team)

Distance covered in 1^st 2 hr :
= 2 × 20
= 40 km
Time taken to cover 60 km distance
= $$\frac{60}{10}$$
= 6 hours
$$\eqalign{ & {\text{Average speed}} \cr & = \frac{{{\text{Total distance}}}}{{{\text{Total time}}}} \cr & = \frac{{100}}{{2 + 6}} \cr & = \frac{{100}}{8} \cr & = 12\frac{1}{2}{\text{ km/hr}} \cr} $$