Answer:
5/12
Explanation:
Here, we want to select the probability that the selected student is a sophomore given that he is a boy
In this case;
P(B) = P(boy)
P(A) = P(sophomore)
What we know is that the probability for any section is simply the number of that section divided by the total number of students which is 12 + 18 = 30
From the table;
P(B) = 12/30
P(An B) = 5/30
So;
P(A|B) = 5/30 divided by 12/30
= 5/30 * 30/12 = 5/12