A 300 m long train crosses a platform in 39 sec while it crosses a signal pole in 9 sec. What is the length of the platform?	Choose the correct choice from the following answers:
A) 389 m
B) 350 m
C) 289 m
D) 799 m
E) 1000 m
Speed = 300/9 = 100/3 m/sec.   Let the length of the platform be x meters.   Then, (x + 300)/39 = 100/3   =&gt; x = 1000 m.   Answer:1000 m
<result>E</result>
A 300 m long train crosses a platform in 39 sec while it crosses a signal pole in 9 sec. What is the length of the platform?