On monday, a toy store sold 4 race cars. on tuesday, it sold 8 race cars. on wednesday, it sold 16 race cars. suppose this pattern continues. how many race cars will the toy store sell on friday? describe a rule then solve. plz do this quick giving away 10 !

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.