Question

If A and B are finite sets, say with n and m elements respectively, what can you say regarding the sizes of A ∪ B? A ∩ B? A − B?

Answer 1

Answer with explanation:

There are two sets A and B having n and m elements.

N(A)=n

N(B)=m

→N(A ∪ B)=Common as well as non common elements of Set A and Set B.

So, N(A∪B) ≤ m +n

→N(A∩B)=Common elements of Both A and B

N(A∩B)<n

N(A∩B)<m

→ N(A∩B)=m or n or m-n or n-m,depending on m>n , or , n> m or if , m=n.

→N (A-B)=Common elements of set A is excluded from set B and remaining elements are written

  =n, if there is no common element

 = n-m, if there is some common element.