Excluding stoppages, the speed of a bus is 70 km/hr and including stoppages, it is 40 km/hr. For how many minutes does the bus stop per hour?  Choose the most appropriate option.
A) 118 min	B) 10 min	C) 18 min	D) 16 min	E) 25 min

Rationale: "due to stoppages , it covers 30 km less . time taken to cover 30 km = 30 / 70 * 60 = 25 min . answer : e"
Answer: E