Shannon swims one fourth of the total rent in cycles three-fifths the remaining route she runs the rest of the route if she runs 3600 meters find the total distance of the rope

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.