Let AAA and BBB be finite sets. Under what condition is the identity P(AΔB)=P(A)ΔP(B)P(A \Delta B) = P(A) \Delta P(B)P(AΔB)=P(A)ΔP(B) true?
Only when A=BA = BA=B
Only when A∩B=∅A \cap B = \emptysetA∩B=∅
Only when one of the sets is empty
Never, for any sets AAA and BBB