a train 360 m long is running at a speed of 45 km / hr . in what time will it pass a bridge 390 m long ?
"speed = 45 * 5 / 18 = 25 / 2 m / sec total distance covered = 360 + 140 = 750 m required time = 750 * 2 / 25 = 40 sec answer : b"
divide(360, multiply(subtract(45, 390), const_0_2778))