The Wilson family was one of the first to come to the U. S. They had 8 children. Assuming that the probability of a child being a girl is .5, find the probability that the Wilson family had:
at least 5 girls?
at most 5 girls?

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.