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. After how much time will the trains meet?	Choose the correct answer:
A) 20/8 sec
B) 20/4 sec
C) 5/2 sec
D) 22/7 sec
E) 60/7 sec
They are moving in opposite directions, relative speed is equal to the sum of their speeds.   Relative speed = (54 + 90)*5/18 = 8*5= 
<gadget id="calculator">8*5</gadget>
<output>40</output>
40 mps.   The time required= d/s = 100/40 = 5/2 sec.Answer:5/2 sec
<result>C</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. After how much time will the trains meet?