What's the probability of, let me just do it in a new color. What's the probability, probability of A given B? I'll do those in the colors. A, given that B has happened. So this is saying, what's the probability, what's the probability, probability of A given B is the probability that he picks a blue garment given that he has picked a shirt. So this, the given B, that restricts our outcomes to these two. And so the probability that he's picked a blue item, well that's one out of the two equally likely ones.