Excluding stoppages, the speed of a bus is 50 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?
Choose the correct choice from the following choices
A) 7 min B) 6 min C) 9 min D) 10 min E) 11 min

Rationale: "due to stoppages , it covers 5 km less . time taken to cover 5 km = ( 5 / 50 ) x 60 = 6 min answer : b"
Answer: B