Question

A,B are any two disjoint sets . is n (AUB)=n(A)+n(B) ? justify your answer​

Answer 1

No n(AUB) is not equal to n(A)+n(B) Because

Consider the situation

If A={1,2,3,4,5,6}

B={4,5,6,7,8,9,}

Then AUB={1,2,3,4,5,6,7,8,9}

Total of n(A)+n(B) is 6+6=12

n(AUB) =9

Therefore, n(A)+n(B) is not equal to n(AUB)