So there's a 424th probability, or if we divide the numerator and denominator by four, it is a 1 6th probability that Erica, a 1 6th probability that Erica rolls doubles. What is probability of B? The probability that the four-sided die is a four. So the probability of B, well, once again, there's 24 equally likely possibilities. And how many of them involve the four-sided die being a four? Well, you have all of these right over here involve a four-sided die being a four. So this is one, two, three, four, five, six of the 24 equally likely possibilities.