Two trains 137 meters and 163 meters in length are running towards each other on parallel lines, one at the rate of 42 kmph and another at 48 kmpb. In what time will they be clear of each other from the moment they meet  Select:
A) 8 sec
B) 10 sec
C) 12 sec
D) 14 sec
E) 16 sec
Explanation:   Relative speed of the trains = (42 + 48)= 
<gadget id="calculator">(42 + 48)</gadget>
<output>90</output>
90 kmph= (90×5/18) m / sec = 25 m /sec.   Time taken by the trains to ‘pass each other   = Time taken to cover (137 + 163) m at 25 m /sec = (300/25)= 
<gadget id="calculator">(300/25)</gadget>
<output>12</output>
12 sec   Answer: Option 12 sec
<result>C</result>
Two trains 137 meters and 163 meters in length are running towards each other on parallel lines, one at the rate of 42 kmph and another at 48 kmpb. In what time will they be clear of each other from the moment they meet