Each square below represents one whole. What percent is represented by the shaded area?

%

Consider the set of all four-digit positive integers less than 2000 whose digits have a sum of 24. what is the median of this set of integers?

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.

Which shows the first equation written in slope-intercept form? 1/2 (2y + 10) = 7x