If you have a bag full of balls. It has 6 blue balls, 6 red balls, and 6 green balls. Let's say you take three balls randomly at a time, what is the probability of you taking one ball of each colour?

In the figure shown below, m < 40 and ab =8. which equation could be used to find x?

2.5 milligrams is equivalent to how many grams

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.