Two trains of length 100 m and 200 m are 100 m apart. They start moving towards each other on parallel tracks, at speeds 54 kmph and 36 kmph. In how much time will the trains cross each other?	Choose the correct choice from the following choices
A) 12 sec	B) 13 sec	C) 15 sec	D) 16 sec	E) 17 sec
D   Relative speed = (54 + 36)* 5/18 = 5 * 5= 
<gadget id="calculator">5 * 5</gadget>
<output>25</output>
25 mps.   The time required= d/s = (100 + 100 + 200)/25   = 400/25= 
<gadget id="calculator">400/25</gadget>
<output>16</output>
16 sec.
<result>D</result>
Two trains of length 100 m and 200 m are 100 m apart. They start moving towards each other on parallel tracks, at speeds 54 kmph and 36 kmph. In how much time will the trains cross each other?