How to know if he doesn't like you the same way?

Draw a scaled copy of the circle using a scale factor of 2

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.

Charlie tosses five coins.what is the probability that all five coins will land tails up.