Two trains of length 100 meters and 200 meters are 630 meters apart. They are moving towards each other on parallel tracks, at speeds of 90 km/h and 72 km/h. After how many seconds will the trains meet?	Choose the correct choice from the following answers
A) 12  B) 14  C) 16  D) 18  E) 20
The speeds are 90000/3600= 
<gadget id="calculator">90000/3600</gadget>
<output>25</output>
25 m/s and 72000/3600= 
<gadget id="calculator">72000/3600</gadget>
<output>20</output>
20 m/s   The relative speed is 45 m/s.   time= 630 / 45= 
<gadget id="calculator">630 / 45</gadget>
<output>14</output>
14 seconds   The answer is 14.
<result>B</result>
Two trains of length 100 meters and 200 meters are 630 meters apart. They are moving towards each other on parallel tracks, at speeds of 90 km/h and 72 km/h. After how many seconds will the trains meet?