Question

$Is ::: n(A-B) = n(A) - n(B) ?$​

Answer 1

ANSWER :

★ No

• ➻ n (A — B) is not equal to n (A) — n (B).

• ➻ n (A — B) = n (A) — n (B) ; this statement is False.

• ➻ n (A — B) = n (A) — n (A ⋂ B)

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❍ Note :-

• ⥀ The difference of any two sets A and B is denoted by A — B. It is the set of all those elements which belongs to A, but does not belong to B

• ⥀ A — B = {x | x ∈ A, but x ∉ B}

• ⥀ n (A — B) refers to the number of elements in the set A — B.

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MORE TO KNOW :

According to Cantor's Concept, "A set is a collection of well defined and distinct objects".

• ✎ The word "well defined" means that given any object it must be possible to tell beyond doubt whether that object belongs to the collection or not.

• ✎ The word "distinct" means that no two elements of the set are same.

• ✎ The objects which are listed in a set are called the "Elements of the set".

• ✎ A set is usually denoted by a capital letter of English alphabet.

• ✎ The elements of a set is usually denoted by small letter of English alphabet.