a train 100 m long crosses a platform 125 m long in 40 sec ; find the speed of the train ?
"d = 100 + 125 = 225 t = 40 s = 225 / 40 * 18 / 5 = 20.25 kmph answer : e"
subtract(multiply(40, multiply(const_60.0, const_0_2778)), 100)