Question 1147922
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Use the general formula


    P(A or B) = P(A) + P(B) - P(A and B).


Substitute the given data into the formula to get an equation


    {{{1/2}}} = {{{1/3}}} + P(B) - {{{1/9}}}.


From the equation, find


    P(B) = {{{1/2}}} - {{{1/3}}} + {{{1/9}}} = {{{9/18 - 6/18 + 2/18}}} = {{{5/18}}}.    <U>ANSWER</U>.
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Solved.