Using 4 independent events is this the correct solution?
I'm thinking the last term "-P(A and B and C and D" should be plus rather than minus.

Thank you for any help with this.

Lance

P(A⋃B⋃C⋃D)

P(A and B and C and D)=P(A)+P(B)+P(C)+P(D)
-P(A and B)-P(A and C)-P(A and D)-P(B and C)-P(B and D)-P(C and D)
+P(A and B and C)+P(A and B and D)+P(A and C and D)+P(B and C and D)
-P(A and B and C and D)