Two trains each 250 m in length are running on the same parallel lines in opposite directions with the speed of 80 kmph and 20 kmph respectively. In what time will they cross each other completely? Choices.
A) 15 sec	B) 18 sec	C) 12 sec	D) 10 sec	E) 11 sec
Explanation:   D = 250 m + 250 m = 500 m   RS = 80 + 20= 
<gadget id="calculator">80 + 20</gadget>
<output>100</output>
100 * 5/18= 250/9   T = 500 * 9/250= 
<gadget id="calculator">500 * 9/250</gadget>
<output>18</output>
18 sec   Answer: Option 18 sec
<result>B</result>
Two trains each 250 m in length are running on the same parallel lines in opposite directions with the speed of 80 kmph and 20 kmph respectively. In what time will they cross each other completely?