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

The number of elements in the set $\{ (a, b) : 2a^2 + 3b^2 = 35, a, b \in Z \} $,where $Z$ is the set of all integers,is

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

Which of the following is an empty set?

Two dice are thrown. The events $A, B$ and $C$ are as follows:
$A:$ getting an even number on the first die.
$B:$ getting an odd number on the first die.
$C:$ getting the sum of the numbers on the dice $\leq 5$.
Describe the event $A$ or $B$.

State which of the following sets are finite or infinite:
$\{ x:x \in N \text{ and } x^2 = 4 \}$