Question

If A={1,2,3,4},B={3,4,5,6} then verify n(AUB)=n(A)+n(B)-n(A∩B)

Answer 1

Solution:

AUB={1,2,3,4,5,6}

n(AUB)=6

A={1,2,3,4}

n(A)=4

B={3,4,5,6}

n(B)=4

A∩B={3,4}

n(A∩B)=2

LHS=n(AUB)

=6

RHS=n(A)+n(B)-n(A∩B)

=4+4-2

=6

Therefore, LHS=RHS

n(AUB)=n(A)+n(B)-n(A∩B)