Finite Set & Infinte Set

Finite Set:

It is possible to count the number of elements of sets

• A = {the students of your school}
• L = {p,q,r,s}

Example:If A = {1, 2, 3}; B = {a, b, c} then find n(A) and n(B).

solution:The set A contains three distinct elements ∴ n(A) = 3
and the set B contains three distinct elements ∴ n(B) = 3

Infinte Set:

It is possible to count the number of elements of sets

• B = {x : x is an even number}
• J = {x : x is a multiple of 7}

Examples:The Infinite sets

1. The set of whole numbers < 10
2. The set of integers < 10

Note:There are no elements in a null set. The cardinal number of that set is 0. ∴ n(φ) = 0