What is probability of A, the probability that Erica rolls doubles? Well, over here we have our sample space of possible outcomes. Each of these are equally likely. And so let's see how many of them there are. There are one, two, three, four by one, two, three, four, five, six. So there are 24 possible outcomes, which makes sense. There's four possible outcomes for the four-sided die and six possible outcomes for the six-sided die.