If you buy 3 pairs of socks with an original cost of $9.99/pair at a discount of 15% with a sales tax of 5%, how much do the socks cost in total?

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

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.

Could someone me with this question i’ve been stuck on it for 20 minutes