It is important to know that probability is the ratio between the possible events and the total number of outcomes.
Having said that, the probability would be
[tex]P=\frac{13}{30}\cdot\frac{17}{29}=\frac{221}{870}\approx0.25[/tex]Hence, the probability 25%, approximately.
It's important to know that the events are dependent because the total number of outcomes changes after selecting the first student.