A train 500 meters long completely crosses a 300 meters long bridge in 45 seconds. What is the speed of the train is?	Choose the correct choice from the following options:
A) 32	B) 28	C) 49	D) 64	E) 21

Rationale: "s = ( 500 + 300 ) / 45 = 800 / 45 * 18 / 5 = 64 answer : d"
Answer: D