Question: 2019 Winter Final - 18

Let $A$ and $B$ be two independent events in some sample space $S$. Recall that $\overline{B}$ denotes the complement of $B$. You are given that $\Pr(A) = 1/4$ and $\Pr(\overline{B}) = 2/3$. What is $\Pr(A \cup B)$?