Class 6th | Unit 1: Numbers | Sets | Revision Notes

Conceptual division:-
• Introduction of Set :
A set is a collection or group of objects/elements which have a similar characters.

• Way of Representing Set
a. Elements of a Set
b. Properties of Set

• Representation of Set
a. Listing Method (Roster form)
b. Rule Method ( Set-builder form)

• Types of Set
a. Equal Sets
b. Empty Set or Null Set or Void Set
c. Non-Empty Set or Overlapping Set
d. Singleton Set
e. Finite Set
f. Infinite Set
g. Null or Empty or Void Set
h. Equivalent Set
i. Disjoint Set
j. Cardinality of Set

• Examples :
• Disjoint Set

Q.1 Two sets are given by A = x , y, z and B = 1,2,3,4,5

Solution : Clearly , sets A and B have no element common to both . Therefore sets A and B
are disjoint sets.

Q.2 Find the cardinality of the set
A = 2 , 4,8,10,12

Solution : Since , set A = 2, 4, 8, 10, 12 has total 5 elements. Hence , the cardinality of the set A
is 5.