A 300 m long train crosses a platform in 30 sec while it crosses a signal pole in 18 sec. What is the length of the platform?  Choose the correct answer.
A) 286 m
B) 350 m
C) 200 m
D) 278 m
E) 267 m
Speed = 300/18 = 50/3 m/sec.   Let the length of the platform be x meters.   Then, (x + 300)/30 = 50/3   x = 200 m.   Answer:200 m
<result>C</result>
A 300 m long train crosses a platform in 30 sec while it crosses a signal pole in 18 sec. What is the length of the platform?