A train speeds past a pole in 15 sec and a platform 120 m long in 25 sec, its length is?
Select.
A) 238 B) 180 C) 988 D) 177 E) 171
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 + 120)/25 = x/15 =&gt; x = 180 m.   Answer: 180
<result>B</result>
A train speeds past a pole in 15 sec and a platform 120 m long in 25 sec, its length is?