a train covers a distance of 54 km in 15 min . if it takes 8 sec to pass a telegraph post , then the length of the train is ?
"speed = ( 54 / 15 * 60 ) km / hr = ( 216 * 5 / 18 ) m / sec = 60 m / sec . length of the train = 60 * 8 = 480 m . answer : option b"
divide(54, subtract(divide(54, 15), 8))