A 600 meter long train crosses a signal post in 40 seconds. How long will it take to cross a 18 kilometer long bridge, at the same speed? Choose the correct choice from the following
A) 14 min	B) 20 min	C) 18 min	D) 19 min	E) 13 min

Rationale: "s = 600 / 40 = 15 mps s = 18000 / 15 = 1200 sec = 20 min . answer : b"
Answer: B