The length of a bridge in meters, which a train 120-meters long and traveling at 45 km/hr can cross in 30 seconds is?  Select the correct option
A) 255 B) 285 C) 315 D) 345 E) 375

Rationale: "45 km / h = 45000 m / 3600 s = 12.5 m / s in 30 seconds , the train can go 30 ( 12.5 ) = 375 meters let x be the length of the bridge . x + 120 = 375 meters x = 255 meters the answer is a ."
Answer: A