a goods train runs at the speed of 72 km / hr and crosses a 250 m long platform in 15 sec . what is the length of the goods train ?
"speed = 72 * 5 / 18 = 20 m / sec . time = 15 sec . let the length of the train be x meters . then , ( x + 250 ) / 15 = 20 x = 50 m . answer : e"
subtract(multiply(multiply(divide(72, const_3600), const_1000), 15), 250)