A train 300 meters long completely crosses a 300 meters long bridge in 45 seconds. What is the speed of the train is?  Choose the most appropriate option.
A) 32	B) 48	C) 29	D) 27	E) 21

Rationale: "s = ( 300 + 300 ) / 45 = 600 / 45 * 18 / 5 = 48 answer : b"
Answer: B