What is the 32nd term of the arithmetic sequence where a1 = 12 and a13 = -60

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.

Assume that y varies inversely with x. if y=1.6 when x=0.5 find x when y=3.2

Math i have no idea how to do a and b