Two trains 200 m and 150 m long are running on parallel rails at the rate of 40 kmph and 45 kmph respectively. In how much time will they cross each other, if they are running in the same direction?  Choose the most appropriate option.
A) 72 sec  B) 132 sec  C) 192 sec  D) 252 sec  E) None
Solution   Relative Speed	= (45 - 40 )= 
<gadget id="calculator">(45 - 40 )</gadget>
<output>5</output>
5 kmph=(5 x 5 / 18)m/sec   = (25 / 18 ) m/sec   Time taken	= (350 x 18 / 25) sec   = 252 sec.   Answer 252 sec
<result>D</result>
Two trains 200 m and 150 m long are running on parallel rails at the rate of 40 kmph and 45 kmph respectively. In how much time will they cross each other, if they are running in the same direction?