Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:
$ 5\, .......\, A$
State whether each of the following set is finite or infinite :
The set of animals living on the earth
Write down all the subsets of the following sets
$\{ a,b\} $
Write down all the subsets of the following sets
$\{ a\} $
State which of the following sets are finite or infinite :
$\{ x:x \in N$ and $x$ is prime $\} $