Question

P(非A)=0.3,P(B)=0.4,P(A*非B)=0.5,求P(B|A并非B)

Answer 1

P(~A)=0.3

P(B)=0.4

P(A~B)=0.5

P(B|AU~B)=P(A,AU~B)/P(AU~B)

=P(AB)/(1-(P(B)-P(AB))

P(AB)=P(A)-P(A~B)=0.2

所以

原式=0.2/0.8=1/4