a train speeds past a pole in 50 seconds and a platform 500 m long in 100 seconds . its length is :
"let the length of the train be x meters and its speed be y m / sec . they , x / y = 50 = > y = x / 50 x + 500 / 100 = x / 50 x = 500 m . answer : option e"
multiply(500, subtract(const_2, const_1))