A train speeds past a pole in 15 sec and a platform 140 m long in 25 sec, its length is? Choose the most appropriate option:
A) 210	B) 150	C) 160	D) 170	E) 180
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.   210nswer: Option 210
<result>A</result>
A train speeds past a pole in 15 sec and a platform 140 m long in 25 sec, its length is?