A train traveling at 72 kmph crosses a platform in 30 seconds and a man standing on the platform in 18 seconds. What is the length of the platform in meters?	Pick one:
A) 240 meters	B) 360 meters	C) 420 meters	D) 600 meters	E) Cannot be determined
Explanation:   Length of the platform = speed of train * extra time taken to cross the platform.   Length of platform = 72 kmph * 12 seconds   Convert 72 kmph into m/sec   1 kmph = 518518 m/s (This can be easily derived. But if you can remember this conversion, it saves a good 30 seconds).   ∴ 72 kmph = 518∗72518∗72 = 20 m/sec   Therefore, length of the platform = 20 m/s * 12 sec = 240 meters.   Correct answer: 240 meters
<result>A</result>
A train traveling at 72 kmph crosses a platform in 30 seconds and a man standing on the platform in 18 seconds. What is the length of the platform in meters?