The answer is 1/3
Explain
So let A be the event that say a freshman
And b be event that say a boy is chosen
So p(A\b ) that is both occur simultane lushly
4/12+18 = 2/15
So p (b) = 12/30 = 6/15
So we know p(A/b) = p (a/b)/ p(b) = 2/5 / 6/5 = 1/3
So the p( freshman/boy is 1/3
I hope this help you
Have a great day/night