A train speeds past a pole in 15 sec and a platform 100 m long in 25 sec, its length is?	Choose the correct choice from the following answers
A) 299 m	B) 982 m	C) 399 m	D) 150 m	E) 354 m
Let the length of the train be x m and its speed be y m/sec.   Then, x/y = 15 =&gt; y = x/15   (x + 100)/25 = x/15 =&gt; x = 150 m.   Answer: 150 m
<result>D</result>
A train speeds past a pole in 15 sec and a platform 100 m long in 25 sec, its length is?