Answer:
D.12
Explanation:
The first thing is to determine the two integer sets, which we will start with the number 1, therefore the first would be:
{1,2,3,4}
We know that it has a number in common, which in this case would have to be 4, therefore, the other set would be:
{4,5,6,7}
Therefore the sets are:
{1,2,3,4}; {4,5,6,7}
Now to calculate the difference between the sum of the integer between them it would be:
(5 - 3) + (6 - 2) + (7 - 1)
= 2 + 4 + 6
= 12
The answer then would be D.12