a train speeds past a pole in 15 seconds and speeds past a platform 100 meters long in 25 seconds . its length in meters is :
"let the length of the train be x metres and its speed be y metres / sec . then x / y = 15 y = x / 15 x + 100 / 25 now , ( x + 100 ) / 25 = x / 15 x = 150 m answer : e"
multiply(100, subtract(const_2, const_1))