Acar can travel 476 miles on 14 gallons of gas. write an equation relating the distance d to the number of gallons g. how many gallons of gas does this car need to travel 578 miles?

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.