Final Cover - For Printing

9. Infinite Set
   A set with uncountable number of elements is said to be an infinite set. In other
   words, if the cardinal number of a set could not be found then the set is said to be an
   infinite set.
   Eg. : C = {1, 2, 3, ...}
   Provide the child with a bowl full of sand grains and ask him/her to count the grains.
   Counting the grains is practically impossible, and now explain the concept of an
   infinite set, orally.
   Note : In other words, a set which is empty or consists of a definite number of
   elements is called finite, other wise the set is infinite.

For example,
Set of days of the week
Set of vowels in the English alphabet

A = { x| 1≤x≤10, x∈^ N}

B = { x| 15>x, x N} are all finite sets, while

N – Set of natural numbers

Z – Set of integers

Q – Set of all rational numbers

C = { x|x>11, x∈N}

the set of points in a line, etc., are all infinite sets.

10. The Null Set / The Empty Set / The Void Set
    A set with no elements is said to be the null set or the empty set or the void set.
    Eg. : B = {Horses with six legs}
    C = { x| x+8 = 4, x∈N}
    D = { x| x+4 = 4, x N}