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 options
A) 8 ½ sec	B) 6 ½ sec	C) 2 ½ sec	D) 7 ½ sec	E) 9 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?