Two bullet train s 140 m and 170 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
A) 15.8 sec.  B) 12.8 sec.  C) 11.16 sec.  D) 10.8 sec.  E) 08.8 sec.
Relative speed = (60 + 40) km/hr = 100x5/18 = 250/9 m/ sec.   Distance covered in crossing each other = (140 + 170)= 
<gadget id="calculator">(140 + 170)</gadget>
<output>310</output>
310 m.   Required time= 310x9/250 = 11.16 sec.   ANSWER 11.16 sec.
<result>C</result>
Two bullet train s 140 m and 170 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: