In a second grade class containing 13 girls and 10 boys, 2 students are selected at random to give out the math papers. what is the probability that the second student chosen is a boy, given that the first one was a girl?

The fact that the first chosen student was a girl is already decided, so there is no need to find the probability of that happening. There are a total of 13+10, or 23 students. A girl was already selected, so that leaves 22 students. The chance that a boy is chosen is 10/22, or 5/11.