Asked by Katie
                Box A contains 3 white marbles and 4 black marbles. Box B contains 6 white marbles and 5 black marbles. An experiment consists of first selecting a marble at random from Box A. The marble is transferred to Box B and then a second marble is drawn from Box B. What is the probability that the first marble was white given that the second marble was white? 
            
            
        Answers
                    Answered by
            Reiny
            
    prob(W from boxA) = 3/7
now we transfer a ball
case1, ball transferred is W
now we have 7white in B
prob(W from boxB) = 7/12
prob as stated = (3/7)(7/12) = 1/4
case 2, ball transferred is B
now we still have 6 W in B
prob(W from B) = 3/7 x 6/12 = 3/14
prob(of our event) = 1/4 + 3/14 = 13/28
                                                    There are no AI answers yet. The ability to request AI answers is coming soon!
                                            
                Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.