excluding stoppages , the speed of a bus is 50 kmph and including stoppages , it is 35 kmph . for how many minutes does the bus stop per hour ?
"explanation : in one hour due to stoppages , it covers 15 km less . time taken to cover 15 km = [ 15 / 50 * 60 ] min = 18 min answer : b"
multiply(const_60, divide(subtract(50, 35), 50))