A train of 50 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 1.5 km long?	Choose the correct choice from the following options.
A) 6
B) 3
C) 4
D) 4.5
E) 2

Rationale: "d = 50 * 60 + 1500 = 3000 m t = 4500 / 60 * 18 / 5 = 270 sec = 4.5 mins answer : d"
Answer: D