In a class of 30 students, there are 17 girls and 13 boys. Five are A students, and three of these students are girls. If a student is chosen at random, what is the probability of choosing a girl or an A student?
I got 19/30:
If three of A students are girls => 2 are boys.
P = P(choose any girl) + P(choose boy who is A) = 17/30 + 2/30 = 19/30.