The length of the bridge, which a train 145 metres long and travelling at 45 km/hr can cross in 30 seconds, is:
Select
A) 200 m  B) 230 m  C) 245 m  D) 250 m  E) 270 m

Rationale: "let the length of the bridge : l the equation now is l + 145 / 12.5 m / s ( 45 km / hr or 12.5 m / s ) = 30 solving , l = 230 m answer : b"
Answer: B