139. Let A and B be two independent events. If $P(A \cap B) = 0.6$ and $P(A \cap B) = 0.2$, then $P(A \cup B')$ is equal to: (1) $0.7$ (2) $0.75$ (3) $0.85$ (4) $0.9$
\textbf{139.} Let A and B be two independent events. If $P(A \cap B) = 0.6$ and $P(A \cap B) = 0.2$, then $P(A \cup B')$ is equal to:
(1) $0.7$ \hfill (2) $0.75$ \hfill (3) $0.85$ \hfill (4) $0.9$
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