Question

What is the cardinal number of following sets?

$K=\left\{lettersintheword\text{'}MADAM\text{'}\right\}$

Answer 1

The number of distinct elements in a finite set is called the cardinal number of the set. It is denoted by $n\left(K\right)$

Given set:

$K=\left\{lettersintheword\text{'}MADAM\text{'}\right\}$

The element of the word $\text{'}MADAM\text{'}$ can be written as $\left\{M,A,D\right\}$

It can be seen clearly there is a number of letters in the word $\text{'}MADAM\text{'}$ is $3$.

Hence, the cardinal number of the set $K=\left\{lettersintheword\text{'}MADAM\text{'}\right\}$ is $n\left(K\right)=3$.