Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is: Choose the correct choice from the following options:  A) 10.8 sec  B) 9.5 sec  C) 7.4 sec  D) 8.9 sec  E) 8.8 sec
Relative speed = (60 + 40) km/hr = 100x5/18 = 250/9 m/ sec.   Distance covered in crossing each other = (140 + 160)= 
<gadget id="calculator">(140 + 160)</gadget>
<output>300</output>
300 m.   Required time= 300x9/250 = 54/5= 
<gadget id="calculator">54/5</gadget>
<output>54/5 = around 10.8</output>
10.8 sec.   10.8 secnswer : 10.8 sec.
<result>A</result>
Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is: