Answer:
[tex]P(B) = 0.3[/tex]
Step-by-step explanation:
We use the following formula for Venn probabilities to solve this question.
[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]
P((AUB)') = 0.4
This means that:
[tex]P(A \cup B) = 1 - P(A \cup B)' = 1 - 0.4 = 0.6[/tex]
We also have that:
[tex]P(A) = 0.5, P(A \cap B) = 0.2[/tex]
What is P(B)?
[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]
[tex]0.6 = 0.5 + P(B) - 0.2[/tex]
[tex]0.3 + P(B) = 0.6[/tex]
[tex]P(B) = 0.3[/tex]
