5. margaret is making fudge for a
party. the recipe calls for
| 1 1/4 cups of sugar and 1 1/4cups of
chocolate chips. how many cups
of sugar and chocolate chips does
margaret need to make the
fudge?

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.