The days maturity for a sample of 5 money market funds areshown here. the dollar amounts invested in the funds areprovided. use the weighted mean to determine the mean numberof days to maturity for dollars invested in these 5 money marketfunds. col1 days tomaturity 20 12 7 5 6col2 $$ value (millions) 20 30 10 15 10

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.