Question
Let $\mathrm{A}$ and $\mathrm{B}$ be two events such that $P(B \mid A)=\frac{2}{5}, P(A \mid B)=\frac{1}{7}$ and $P(A \cap B)=\frac{1}{9} \cdot$ Consider
(S1) $P\left(A^{\prime} \cup B\right)=\frac{5}{6}$,
(S2) $P\left(A^{\prime} \cap B^{\prime}\right)=\frac{1}{18}$
Then :