A 300 m long train crosses a platform in 39 sec while it crosses a signal pole in 12 sec. What is the length of the platform?  Answers.
A) 187 m  B) 350 m  C) 267 m  D) 287 m  E) 675 m
Speed = 300/12= 
<gadget id="calculator">300/12</gadget>
<output>25</output>
25 m/sec.   Let the length of the platform be x meters.   Then, (x + 300)/39=25   =&gt; x = 675 m.   Answer:675 m
<result>E</result>
A 300 m long train crosses a platform in 39 sec while it crosses a signal pole in 12 sec. What is the length of the platform?