A train 100 meters long completely crosses a 300 meters long bridge in 30 seconds. What is the speed of the train is?	Choices.
A) 32 kmph	B) 48 kmph	C) 34 kmph	D) 43 kmph	E) 40 kmph

Rationale: "s = ( 100 + 300 ) / 30 = 400 / 30 * 18 / 5 = 48 answer : b"
Answer: B