A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is: Choose the most appropriate option
A) 50 m
B) 150 m
C) 200 m
D) data inadequate
E) None of these
Explanation:   Let the length of the train be x metres and its speed be y m/sec.   Then, (x/y)= 15 y =(x/15)   =x+100/25=x/15   =&gt; 15(x + 100) = 25x   =&gt; 15x + 1500 = 25x   =&gt; 1500 = 10x   =&gt; x = 150 m.   Answer: 150 m
<result>B</result>
A train speeds past a pole in 15 seconds and a platform 100 m long in 25 seconds. Its length is: