Each guest at casandras party had 3 turns to act out worlds during a game. They began with a list of 50 words. When they finished there were 5 words left. How many guests were at her party??

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.