Four gallons of paint are used to paint 25 chair. if each chair used the same amount of paint how many gallons are used to paint each chair? between what two whole number does your answer lie

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.