Suppose that in class of $30$ students,there are $17$ girls and $13$ boys. Five are A students from which three are girls. If random student is chosen, what is a probability that student is a girl or an A student.
I did not understand are A students other class? from $30$ students, probability of girl is $17/30$, from A students, probability is $3/5$, but what about the combination of this probabilities?