Write the letter of the correct answer

I need napo

Amachine part consists of a half sphere and a cylinder, as shown in the figure. the total volume of the part is π cubic inches.

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.

Layla answer 21 of the 25 questions on his history test correctly.what decimal represents the fraction of problem he answer incorrectly.