Let A and B be two events such that \(P(A / B)=\frac{1}{2}\) and \(P(B / A)=\frac{1}{3}\) and \(P(A \cap B)=\frac{1}{6}\) then, which one of the following is not true?
1
A and B are not independent
2
\(P(A \cup B)=\frac{2}{3}\)
3
\(P\left(A^{\prime} \cap B\right)=\frac{1}{6}\)
4
A and B are independent