A train 150 meters long completely crosses a 320 meters long bridge in 40 seconds. What is the speed of the train is?
Choose the correct answer:
A) 32	B) 42	C) 54	D) 66	E) 09

Rationale: "s = ( 150 + 320 ) / 40 = 470 / 40 * 18 / 5 = 42 answer : b"
Answer: B