We are given  P(M) = 0.4;  P(W) = 0.5;  and  P(M|W) = 0.7.


The latest means that   = 0.7,  which implies  P(MnW) = 0.7*P(W) = 0.7*0.5 = 0.35.


Now I am in position to answer the questions:


    (A)  The probability under (A) is  P(MnW) = 0.35.     ANSWER


    (B)  The probability under (B) is  P(W|M) =  =  = .    ANSWER


    (C)  The probability under (C) is  P(M U W) = P(M) + P(W) - P(MnW) = 0.5 + 0.4 - 0.35 = 0.55.    ANSWER