Two trains 210 m and 260 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? Choose the correct choice from the following answers.
A) 16.92 sec B) 14.8 sec C) 10.68 sec D) 10.8 sec E) 20.8 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 = 210 + 260= 
<gadget id="calculator">210 + 260</gadget>
<output>470</output>
470 m.   Required time= 470 * 9/250= 
<gadget id="calculator">470 * 9/250</gadget>
<output>423/25 = around 16.92</output>
16.92= 16.92 sec.   16.92 secnswer: 16.92 sec
<result>A</result>
Two trains 210 m and 260 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?