If A and B are independent events such that P(A) = 0.3, $P(A \cup \bar{B})$= 0.8, then P(B) equals to
Answer & explanation
Correct answer: option 2
$P(A)+P(\bar{B})-P(A) P(\bar{B})=0.8$
$0.3+(1-x)-0.3(1-x)=0.8$
$(1-x)(0.7)=0.5$
$1-x=\frac{5}{7} \Rightarrow x=1-\frac{5}{7}=\frac{2}{7}$