Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Choose the correct choice from the following answers:  A) 6 ½ sec  B) 9 ½ sec  C) 3 ½ sec  D) 7 ½ sec  E) 2 ½ sec
\70 + 50= 
<gadget id="calculator">70 + 50</gadget>
<output>120</output>
120 * 5/18= 100/3 mps   7 ½ sec = 150 + 100= 
<gadget id="calculator">150 + 100</gadget>
<output>250</output>
250 m   T= 250 * 3/100 = 15/2 = 7 ½ sec   Answer:7 ½ sec
<result>D</result>
Two trains are moving at 50 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?