A train speeds past a pole in 15 sec and a platform 140 m long in 25 sec, its length is? Choose the correct choice from the following options
A) 50 m
B) 150 m
C) 210 m
D) 300 m
E) None of these
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 + 140)/25 = x/15 =&gt; x = 210 m.   ANSWER:210 m
<result>C</result>
A train speeds past a pole in 15 sec and a platform 140 m long in 25 sec, its length is?