Two trains 170 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 which they take to cross each other is?
Choose the correct choice from the following: A) 10.9 B) 10.7 C) 10.3 D) 11.88 E) 12.2
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 = 170 + 160= 
<gadget id="calculator">170 + 160</gadget>
<output>330</output>
330 m.   Required time= 330 * 9/250 = 297/25= 
<gadget id="calculator">297/25</gadget>
<output>297/25 = around 11.88</output>
11.88 sec.   'Answer: 11.88
<result>D</result>
Two trains 170 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 which they take to cross each other is?