Tim is buying packages of paper plates & cups. he wants to have equal amounts of each, but plates come in 24 per pack and cups come in 16 per pack. what is the least amount of plates & cups tim will buy to get the same number of each ?

a. 8
b. 16
c. 24
d. 48

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.