Let X and Y be two sets.Statement 1:X∩(Y∪X)′=ϕStatement 2:  If X∪ Y has m elements and X∩ Y has n elements then symmetric difference X ∆ Y has m – n elements.

X∩(Y∪X)′=X∩Y′∩X′=X∩X′∩Y′=ϕStatement-1 is True.XΔY=(X~Y)∪(Y~X)=(X∪Y)~(X∩Y)⇒number of elements in X ∆Y = m – n. ⇒ Statement-2 is True but does explain statement-1.