Video Explanation

Text Explanation

To determine the average of x and y, we would need to know their sum.  From the information given in the prompt, we know that:

x + y + w = 21
x + y = 21 – w

This means that the average of x and y is:

However, we have no idea what the value of w is, so the average of x and y could be less than, equal to, or greater than 7.  For example:

w = 1

10
Column A's 10 > Column B's 7

w = 11

5
Column A's 5 < Column B's 7

Therefore, the relationship cannot be determined.