If P(A)=0.3P(A) = 0.3P(A)=0.3 and P(A∪B)=0.5P(A \cup B) = 0.5P(A∪B)=0.5, and AAA and BBB are mutually exclusive, what is P(B)P(B)P(B)?
0.20.20.2
0.80.80.8
0.150.150.15
0.40.40.4