A 300 metre long train crosses a platform in 39 seconds while it crosses a signal pole in 18 seconds. What is the length of the platform?	Choose the correct choice from the following answers.
A) 320 m  B) 350 m  C) 650 m  D) None of these  E) Cannot be determined
Solution   Speed	= (300 / 18) m/sec   = (50 / 3) m/sec.   Length of the platform be x metres.   Then	= x + 300 /39   = 50 / 3 m/sec   = 3 (x + 300) =1950 .   = 350 m   Answer 350 m
<result>B</result>
A 300 metre long train crosses a platform in 39 seconds while it crosses a signal pole in 18 seconds. What is the length of the platform?