Question 1194157
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You have  P(B given A) = 0.8.


By the definition of the <U>conditional probability</U>, it means that  P(A and B) / P(A) = 0.8,  or  {{{P(A_and_B)/P(A)}}} = 0.8,  or

    {{{P(A_and_B)/0.31}}} = 0.8.


It implies that


    P(A and B) = 0.8*0.31 = 0.248.    <U>ANSWER</U>
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Solved, answered and explained.