# Set definition in math explained with example

Learn and know what is the set definition in math. In the school level we will learn about set in the class 9 onwards and which continues up to class 12. The chapter “relations and functions” dependent upon the set chapter. So if you won’t study sets first then relations and functions chapter you cannot understand.

The word “set” we will use in our daily frequently in some situations. For example, if we have some books then we say that I have a set of books. If we have 3 or 4 pens then also we say that I have set of pens. Like this we are using the word “set” in our daily life. Do you know the exact meaning of what is a set? Suppose if you don’t know, it’s not at all a problem. Now we will know and learn everything about sets and here understanding the set definition is very important.

## Definition of a set in mathematics as follows:

In mathematics, the definition of a set is given as “any collection of well defined things/objects are called as set”. This means whatever we are collecting if it is well defined then we say that collection as a set otherwise we say that it is not a set. In the set definition the word “well defined” plays an important role in deciding a set or not a set.

### Examples which represents sets are given below

“Collection of all the names of the months which has 30 days in a month” is a set. We have totally 12 moths, in that the months April, June, September and November have 30 days in a month. As it is satisfying set definition, so we call it as a set.

“Collection of all the mandals in a district” is a set. Easily we can recognize all the mandals and list them. Which means it is well defined and satisfies set definition.

#### Examples which does not represent sets as follows

“Collection of all the student’s names from section B in a school” is not a set. Because which class is not mentioned, we say that it is not well defined sentence.

“The Collection of all the motorbikes” is not a set. Because the motorbike company is not mentioned, so it shows that it is not well defined.