A 300 m long train crosses a platform in 39 sec while it crosses a signal pole in 14 sec. What is the length of the platform? Choose the correct choice from the following choices
A) 287 m	B) 350 m	C) 267 m	D) 535.71 m	E) 656 m

Rationale: "speed = 300 / 14 = 150 / 7 m / sec . let the length of the platform be x meters . then , ( x + 300 ) / 39 = 150 / 7 = > x = 535.71 m . answer : d"
Answer: D