a train is 400 meter long is running at a speed of 60 km / hour . in what time will it pass a bridge of 800 meter length ?
"speed = 60 km / hr = 60 * ( 5 / 18 ) m / sec = 150 / 9 m / sec total distance = 400 + 800 = 1200 meter time = distance / speed = 1200 * ( 9 / 150 ) = 72 seconds answer : a"
divide(add(400, 800), divide(multiply(60, const_1000), const_3600))