Here are the numbers of children in 11 elementary school classes.
Sto se
18, 16, 17, 17, 20, 16, 16, 17, 19, 19, 19
Find the modes of this data set.

Which representation has a constant of variation of -2.5

The weight v of an object on venus varies directly with its weight e on earth. a person weighing 120 lb on earth would weigh 106 lb on venus. how much would a person weighing 150 lb on earth weigh on venus?

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.