a train running at the speed of 72 km / hr crosses a pole in 9 sec . what is the length of the train ?
"speed = 72 * 5 / 18 = 20 m / sec length of the train = speed * time = 20 * 9 = 180 m answer : e"
multiply(divide(multiply(72, const_1000), const_3600), 9)