Question

Write the cardinal number for the set $C=\left\{0\right\}$.

Answer 1

Cardinal number is the number of elements in a finite set. If there is a set $A$, then its cardinal number is denoted as $n\left(A\right)$.

The number of elements in set $C$ is $1$, i.e., $0$. Although it is zero but still it is an element of the set.

Hence the cardinal number will be $n\left(C\right)=1$.