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QUESTION
Given that $A$ and $B$ are independent events with $p(A)=0.5$ and
$p(B)=0.3$, find the probability that one and only one of the
events occurs.
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ANSWER
$p(A)=0.5,$ therefore $p($not$A)=1-0.5=0.5\\ p(B)=0.3,$ therefore
$p($not $B)=0.7\\ p(1$ event$)=p((A$ and not $B)$ or $(B$ and not
$A))=(0.5)(0.7)+(0.3)(0.5)=0.5$
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