Q. 18

# Mark the correct alternative in the following:

If A and B are two sets such that n(A) = 70, n(B) = 60, n= 110, then n is equal to

A. 240

B. 50

C. 40

D. 20

Answer :

n(A⋃B) =n(A)+n(B)-n(A⋂B)

∴n(A⋂B) =n(A)+n(B)-n(A⋃B)

∴n(A⋂B) =70+60-110

∴n(A⋂B) =20

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