Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour ?

A. 9 min

B. 10 min

C. 12 min

D. 20 min

Answer: Option B

Solution(By Examveda Team)

Due to stoppages, it covers 9 k less.
Time taken to cover 9 km :
$$\eqalign{ & = \left( {\frac{9}{{54}} \times 60} \right){\text{ min}} \cr & = 10\min \cr} $$