Which set is the subset of all given sets

The number of non-empty subsets of the set $\{1, 2, 3, 4\}$ is

Let $A=\{1,2,3,4,5,6\} .$ Insert the appropriate symbol $\in$ or $\notin$ in the blank spaces:

$ 5\, .......\, A$

Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?

$\varnothing \subset A$

Make correct statements by filling in the symbols $\subset$ or $ \not\subset $ in the blank spaces:

$\{ x:x$ is a circlein the plane $\}  \ldots \{ x:x$ is a circle in thesame plane with radius $1$ unit $\} $

If a set $A$ has $n$ elements, then the total number of subsets of $A$ is