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 90 kmph. In how much time will the trains cross each other?	Options:
A) 10 sec B) 11 sec C) 12 sec D) 60/7 sec E) 90/7 sec
A   Relative speed = (54 + 90)* 5/18 = 8 * 5= 
<gadget id="calculator">8 * 5</gadget>
<output>40</output>
40 mps.   The time required= d/s = (100 + 100 + 200)/35   = 400/40= 
<gadget id="calculator">400/40</gadget>
<output>10</output>
10 sec.
<result>A</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 90 kmph. In how much time will the trains cross each other?