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

Write the following interval in set-builder form: $(-3, 0)$

Let $a, b, c$ be real numbers. $A$ set formed with $a, b, c$ whose order of occurrence is preassigned is called:

If $A = \{1, 2, 3, 4, 5\}$, then which of the following statements is not true?

Make correct statements by filling in the symbols $\subset$ or $\not\subset$ in the blank spaces:
${ x:x \text{ is a triangle in a plane} } \dots { x:x \text{ is a rectangle in the plane} }$

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