Astore pays its salespeople on a salary plus comission basis. the store pays a 3.2% commission on sales over a weekly quota. the sales of 4 employees for last week are shown below. find for each person the amount of commission and total earnings for the week.

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.