a goods train runs at the speed of 72 kmph and crosses a 250 m long platform in 30 seconds . what is the length of the goods train ?
"explanation : speed = [ 72 x ( 5 / 18 ) ] m / sec = 20 m / sec . time = 30 sec . let the length of the train be x metres . then , [ ( x + 250 ) / 30 ] = 20 = > x + 250 = 600 = > x = 350 . answer : b"
multiply(subtract(30, divide(250, multiply(const_0_2778, 72))), multiply(const_0_2778, 72))