If $P(A ∩ B)=\frac{1}{2}, P(\overline{A} ∩ \overline{B})=\frac{1}{2}$ and $2P(A)=P(B)=p$, then the value of p is equal to |
$\frac{1}{2}$ $\frac{2}{3}$ $\frac{1}{4}$ $\frac{1}{3}$ |
$\frac{2}{3}$ |
We have, $P(A ∩ B)=\frac{1}{2}, P(\overline{A} ∩ \overline{B})=\frac{1}{2}$ and $ 2P(A)=P(B)=p$ Now, $ P(\overline{A} ∩ \overline{B})=\frac{1}{2}$ $⇒ P(\overline{A ∪ B})=\frac{1}{2}$ $⇒ 1- P (A ∪ B) =\frac{1}{2}$ $⇒ P (A ∪ B) =\frac{1}{2}$ $⇒P(A) +P(B)- P(A ∩ B)=\frac{1}{2}$ $⇒ \frac{p}{2} +p -\frac{1}{2}=\frac{1}{2}⇒ \frac{3p}{2}=1⇒p=\frac{2}{3}$ |