Two trains of length 100 m and 200 m are 100 m apart. They start moving towards each other on parallel tracks, at speeds 90 kmph and 126 kmph. In how much time will the trains cross each other?
Choose the correct answer:
A) 87/7 sec
B) 80/7 sec
C) 80/9 sec
D) 80/5 sec
E) 20/3 sec
Relative speed = (90 + 126)* 5/18 = 12 * 5= 
<gadget id="calculator">12 * 5</gadget>
<output>60</output>
60 mps.   The time required= d/s = (100 + 100 + 200)/60   = 400/60 = 20/3 sec.   Answer: 20/3 sec
<result>E</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 90 kmph and 126 kmph. In how much time will the trains cross each other?