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 minutes

B. 10 minutes

C. 12 minutes

D. 20 minutes

Answer: Option B

Solution(By Examveda Team)

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