P(AUBUC)=P(A)+P(B)+P(C)-P(A and B)-P(A and C)-P(C and B)+P(A and B and C)
其中P(A and B and C)=0=P(B and C) 因为B和C不能一起发生
P(A and B)=P(A)*P(B)=0.1925 因为A,B为相互独立事件
最后,带入数据
P(AUBUC)=0.55+0.35+0.15-0.12-0.1925=0.7375
P(AUBUC)=P(A)+P(B)+P(C)-P(A and B)-P(A and C)-P(C and B)+P(A and B and C)
其中P(A and B and C)=0=P(B and C) 因为B和C不能一起发生
P(A and B)=P(A)*P(B)=0.1925 因为A,B为相互独立事件
最后,带入数据
P(AUBUC)=0.55+0.35+0.15-0.12-0.1925=0.7375