State whether 25 prime, composite or neither

What are the exclude value of mn+3m

What is the radical expression that is equivalent to the expression 27 1 over 5?

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.