a train speeds past a pole in 12 seconds and a platform 160 m long in 17 seconds . its length is ?
"let the length of the train be x meters and its speed be y m / sec . they , x / y = 12 = > y = x / 12 x + 160 / 17 = x / 12 x = 384 m . answer : a"
multiply(160, subtract(const_2, const_1))