A train 600 m long passed a pole in 12 sec. How long will it take to pass a platform 450 m long?
Choose the correct choice from the following options: A) 19 B) 20 C) 21 D) 22 E) 23
Speed = 600/12= 
<gadget id="calculator">600/12</gadget>
<output>50</output>
50 m/sec.   Required time= (600 + 450)/50= 
<gadget id="calculator">(600 + 450)/50</gadget>
<output>21</output>
21 sec.   Answer:21
<result>C</result>
A train 600 m long passed a pole in 12 sec. How long will it take to pass a platform 450 m long?