excluding stoppages , the speed of a bus is 72 kmph and including stoppages , it is 45 kmph . for how many minutes does the bus stop per hour ?
"due to stoppages , it covers 9 km less . time taken to cover 67 km = ( 67 / 72 ) x 60 = 55.8 min answer : e"
multiply(const_60, divide(subtract(72, 45), 72))