excluding stoppages , the speed of a bus is 50 kmph and including stoppages , it is 43 kmph . for how many minutes does the bus stop per hour ?
"d 8.4 min due to stoppages , it covers 7 km less . time taken to cover 9 km = ( 7 / 50 x 60 ) min = 8.4 min"
multiply(const_60, divide(subtract(50, 43), 50))