If $A, B,$ and $C$ are three sets,then $A \cap (B \cup C) =$

If $A = \{1, 2, 3, 4, \dots, 10\}$, then the number of non-empty subsets of $A$ containing only even numbers is

In each of the following,determine whether the statement is true or false. If it is true,prove it. If it is false,give an example.
If $A \subset B$ and $x \notin B,$ then $x \notin A$.

Write the set $\{ x : x \text{ is a positive integer and } x^2 < 40 \}$ in the roster form.

In the following,state whether $A=B$ or not:
$A=\{a, b, c, d\} ; B=\{d, c, b, a\}$

Find the pairs of equal sets,if any,give reasons:
$A = \{ 0 \}$
$B = \{ x : x > 15 \text{ and } x < 5 \}$
$C = \{ x : x - 5 = 0 \}$
$D = \{ x : x^2 = 25 \}$
$E = \{ x : x \text{ is an integral positive root of the equation } x^2 - 2x - 15 = 0 \}$