Sets and Examples

The collection of intelligent students in a class

The collection of beautiful flowers

The collection of prime numbers less than 20

The collection of expensive books

The set of natural numbers less than 1

The set of vowels in the English alphabet

The set of even numbers less than 10

The set of months in a year

The order of elements is important.

Elements may be repeated multiple times.

Each element is listed only once.

A set cannot contain numbers.

{2,4}

{7}

{a,b,c}

∅

4

5

6

10

⊆

∈

∪

∩

The set of months in a year

The set of weekdays

The set of natural numbers

The set of vowels

They have the same number of elements.

They contain exactly the same elements.

They are both finite.

They are both infinite.

{x∣x is an even natural number less than 10}

{2,4,6,8}

{x∣x>0}

{x∣x is prime}