Question

if A={1,2,3},B={3,4} so proved n(aub)=n(a)+n(b)-n(anb)​

Answer 1

Step-by-step explanation:

AUB={1,2,3,4}

n(AUB)=4

LHS:n(AUB)=4

n(A)=3,n(B)=2

A∩B={3}

n(A∩B)=1

so,n(A)+n(B)-n(A∩B)=3+2-1

=4

so, n(AUB)=n(A)+n(B)-n(A∩B)