There is 5 blue marbles, 2 black marbles, and 3 red marbles. In other words, there is a total of 10 marbles.
There are only 2 black marbles and 8 marbles that are not black. Therefore, the probability of <em>not</em> drawing a black marble is 8/10 or 4/5 or 80%.
There are only 3 red marbles out of the 10 total marbles. Therefore, the probability of drawing a red marble is 3/10 or 30%.
