PLS help ! : ) Sam and bobby want to know who cycled faster. The table shows the total miles Sam traveled shows the total miles Sam traveled over time. The graph shows the same relationship for Buddy . Who cycled faster?

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.