Two trains of length 100 m and 200 m are 100 m apart. They start moving towards each other on parallel tracks, at speeds 108 kmph and 72 kmph. In how much time will the trains cross each other?	Options:
A) 8
B) 7
C) 9
D) 2
E) 1
Relative speed = (108 + 72)* 5/18= 
<gadget id="calculator">(108 + 72)* 5/18</gadget>
<output>50</output>
50 mps.   The time required= d/s = (100 + 100 + 200)/50   = 400/50= 
<gadget id="calculator">400/50</gadget>
<output>8</output>
8 sec.   8nswer:8
<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 108 kmph and 72 kmph. In how much time will the trains cross each other?