All about Sets

Q. What is Set?

Ans: A Set is a well defined collection of distinct objects.
The elements of a set are called its members. The members are generally written in small alphabets while the set it self is expressed by a capital alphabet and the set is closed in curly brackets.



well defined means, something that can be defined in words and here distinct means "clear" so a set is a collection of things which we can clearly define.

for example:-

A set of chairs, A set of students, A set of students who read in class ten. etc

Q What are types of Set?

Ans. There are generally four types of sets.

1. Empty/Null Set:

A set which has no members or elements such a set is called Empty or Null set.

{x € R| 5<x>5 } = { } or ∅

2. Singleton Set:

A set which contain only one element is called a singleton set.

{x € R| 1<x<3 } = { 2 }

3. Finite Set:

A finite set is a set which has a limit, its member are in a fixed quantity.

{x € R| 1<x<10 } = { 2,3,4,5,6,7,8,9 }

4. Infinite Set:

Infinite set is the opposite of finite set. Its member have no limit and they are not countable.

{x € R| x>0 } = { 1,2,3,4,5,6,7,8,9, ... }