a 1200 m long train crosses a tree in 120 sec , how much time will i take to pass a platform 500 m long ?
"l = s * t s = 1200 / 120 s = 10 m / sec . total length ( d ) = 1700 m t = d / s t = 1700 / 10 t = 170 sec answer : b"
divide(add(1200, 500), divide(1200, 120))