a 1400 m long train crosses a tree in 100 sec , how much time will it take to pass a platform 700 m long ?
"l = s * t s = 1400 / 100 s = 14 m / sec . total length ( d ) = 2100 m t = d / s t = 2100 / 14 t = 150 sec answer : c"
divide(add(1400, 700), divide(1400, 100))