What time is it?
use the digit in the thousands place
1 for the hour. use the hundreds and
tens place for the minutes.
the
draw the hands on the clock 1,423

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.