If X and Y are two sets such that n(X)=17,n(Y)=23 and n(X u Y ) = 38, find n(XU Y)

If X and Y are two sets such that n(X)=17,n(Y)=23 and n(X u Y ) = 38,

1.	If X and Y are two sets such that n(X)=17,n(Y)=23 and n(X u Y ) = 38, find n(XU Y)
Answer» It is given that:n(X)=17,n(Y)=23,n(X∪Y)=38n(X∩Y)=?Using the formulan(X∪Y)=n(X)+n(Y)−n(X∩Y)∴38=17+23−n(X∩Y)⇒n(X∩Y)=40−38=2∴n(X∩Y)=2