If A and B are two sets such that n(A) = 20, n(B) = 25 and n = 40, then write n .

Question

Philoid · Accepted Answer

n(A⋃B)=n(A)+n(B)-n(A⋂B)

∴n(A⋂B)=n(A)+n(B)-n(A⋃B)

∴n(A⋂B)=20+25-40=5

∴n(A⋂B)=5