概率论,14题
1个回答

------------已知

P(-A)=0.3 , P(B)=0.4 ,P(A-B)=0.5

------------求

P(B|AU-B)

------------解

P(A)=1-P(-A)=1-0.3=0.7

P(AB)=P(A)-P(A-B)=0.7-0.5=0.2

P(AU-B)=P(AB)+P(-B)=0.2+1-0.4=0.8

P(B|AU-B)=P(AB|AU-B)=P(AB)/P(AU-B)=0.2/0.8=0.25