A weather service records 28.8 inches of rain over a 12 month period. What is the average rainfall per month for the year? A:
A)
17 inches
B)
2.4 inches
o
2.9 inches
D)
3.1 inches

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.