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) 155 m
B) 150 m
C) 187 m
D) 177 m
E) 186 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>B</result>
A train speeds past a pole in 15 sec and a platform 100 m long in 25 sec, its length is?