9. The graph below represents the number of soft drinks required for a picnic, depending on the number of students attending the picnic. Soft Drinks Required
27
24
21
Number of Soft Drinks
5. 이 이
Number of Students (s)
If s represents the number of students attending the picnic, which expression represents the number of soft drinks required?
O 1.8
O 2.5
0 3.5

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.