Question

if A and B are two sets and U is the universal set such that n(U)=700, n(A)=200, n(B)=300, n(A∩B)=100. find n(A1∩B1)

Answer 1

n(A' intersection B') = n (AUB)'

=n(U)-n(AUB)...........1

n(AUB)=n(A)+n(B)-n(A intersection B)

=>n(AUB)=200+300-100

=>n(AUB)=400

n(AUB) =400 in 1.....

n(A' intersection B') =n(U)-n(AUB)

=>n(A 'intersection B')=700-400

=>n(A' intersection B') = 300