A 300 m long train crosses a platform in 39 sec while it crosses a signal pole in 36 sec. What is the length of the platform? Options
A) 389 m B) 350 m C) 289 m D) 299 m E) 25 m

Rationale: "speed = 300 / 36 = 25 / 3 m / sec . let the length of the platform be x meters . then , ( x + 300 ) / 39 = 25 / 3 = > x = 25 m . answer : e"
Answer: E