Excluding stoppages,the speed of the bus is 54kmph and
including stoppages,it is 36kmph. For how many minutes does the bus stop per hr	Choose the most appropriate option:  A) 12 min  B) 11 min  C) 13 min  D) 19 min  E) 20 min

Rationale: due to stoppages , it covers 18 km less . time taken to cover 18 km is [ 18 / 54 * 60 ] min = 20 min answer is e .
Answer: E