A bullet train passes a station platform in 36 seconds and a man standing on the platform in 21 seconds. If the speed of the bullet train is 54 km/hr, what is the length of the platform?  Pick one:	A) 240 m	B) 220 m	C) 260 m	D) 225 m	E) 239 m
A   225 M   Speed = 54 x 5/18 = 15 m/s   Length of the bullet train = (15 x 21)m = 315 m.   Let the length of the platform be x metres.   Then, (x + 315)/36 = 15   --&gt; x + 315 = 540   x = 225m. 225 m
<result>D</result>
A bullet train passes a station platform in 36 seconds and a man standing on the platform in 21 seconds. If the speed of the bullet train is 54 km/hr, what is the length of the platform?