A 250 meter long train crosses a platform in 40 seconds while it crosses a signal pole in 20 seconds. What is the length of the platform?	Choose the correct choice from the following answers.
A) 500	B) 1000	C) 350	D) 250	E) 20
Speed = [250 / 20] m/sec =25/2 m/sec.   Let the length of the platform be x meters.   Then, x + 250 /40 = 25/2   2(x + 250) = 1000 è x = 250m. Answer: 250
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A 250 meter long train crosses a platform in 40 seconds while it crosses a signal pole in 20 seconds. What is the length of the platform?