Element of Set

The objects used to form a set are called its element or its members.

Generally, the elements of a set are written inside a pair of curly (idle) braces and are represented by commas. The name of the set is always written in capital letter.

Example :
 If set S = {teacher, student, staff, librarian, gardener}. State which of the following statements are ‘correct’ and which are ‘wrong’ and explain the statement. (S = School)

(i)  bag ∈ S

(ii)  teacher ∈ S

(iii) student ∈ S

(iv) pencil box ∈ S

Solution:

(i) bag ∈ S

Wrong, since bag does not belongs to  set S i.e. bag ∉ S

(ii) teacher ∈ S

Correct, since teacher belongs to  set S.

(iii) student ∈ S

Correct, since student belongs to  set S.

(iv) pencil box ∈ S

Wrong, since pencil box does not belongs to set S i.e. pencil box ∉ S

Reference : http://www.mathwords.com/e/element_of_a_set.htm