A train speeds past a pole in 50 seconds and a platform 500 m long in 100 seconds. Its length is:
Choose the correct choice from the following choices:	A) 550 m.	B) 300 m.	C) 600 m.	D) 400 m.	E) 500 m.
Let the length of the train be x meters and its speed be y m/sec.   They, x / y = 50 =&gt; y = x/50   x + 500 / 100 = x / 50   x = 500 m.   Answer: Option 500 m.
<result>E</result>
A train speeds past a pole in 50 seconds and a platform 500 m long in 100 seconds. Its length is: