A store sells 24 greeting cards for $12. Select the three unit rates that describe this sale. CLEAR CHECK 2 cards per dollar $0.50 per card 10 cards per $5 $6 per dozen cards

Evaluate cos2θ for cosθ = square root of 3/2

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.

Sum of the interior angles of a pentagon