After taking core samples all over a cone-shaped mountain, you have determined that for every 1,000,000 yd3 there is about 2 lbs of gold to be mined. if the mountain has a base that is 2,000 yards wide and a height that is 3,000 yards tall, about how much gold is it expected to hold?

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.