Excluding stoppages, the speed of a bus is 75 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?  Choose one.
A) 15 B) 24 C) 17 D) 19 E) none of these

Rationale: "due to stoppages , it covers 30 km less . time taken to cover 30 km = ( ( 30 / 75 ) ã — 60 ) = 24 min . option ( b ) is correct"
Answer: B