Two trains 140 m and 180 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time which they take to cross each other is? Answers:	A) 11.52 sec	B) 10.1 sec	C) 10.6 sec	D) 10.8 sec	E) 10.2 sec
Relative speed = 60 + 40= 
<gadget id="calculator">60 + 40</gadget>
<output>100</output>
100 km/hr.= 100 * 5/18 = 250/9 m/sec.   Distance covered in crossing each other   = 140 + 180= 
<gadget id="calculator">140 + 180</gadget>
<output>320</output>
320 m.   Required time= 320 * 9/250= 
<gadget id="calculator">320 * 9/250</gadget>
<output>288/25 = around 11.52</output>
11.52 sec.   11.52 secnswer:11.52 sec
<result>A</result>
Two trains 140 m and 180 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time which they take to cross each other is?