Let's do a couple of exercises from our probability one module. So we have a bag with nine red marbles, two blue marbles, and three green marbles in it. What is the probability of randomly selecting a non-blue marble from the bag? So let's draw this bag here. So that's my bag, and we're going to assume that it's a transparent bag. That looks like a vase. But we have nine red marbles, so let me draw nine red marbles.