If $A$ and $B$ are two sets,then $A \cup (A \cap B)$ is equal to

Determine whether the following set is finite or infinite:
$\{1, 2, 3, \ldots, 99, 100\}$

State which of the following sets are finite or infinite: $\{ x:x \in N \text{ and } 2x - 1 = 0 \}$

Decide,among the following sets,which sets are subsets of one another:
$A = \{ x: x \in \mathbb{R} \text{ and } x \text{ satisfies } x^2 - 8x + 12 = 0 \},$
$B = \{2, 4, 6\}, C = \{2, 4, 6, 8, \dots\}, D = \{6\}$

Which of the following is not an example of the null set?

Write the following set in roster form:
$B = \{x : x \text{ is a natural number less than } 6\}$