If the set $A$ has $3$ elements and the set $B = \{3, 4, 5\},$ then find the number of elements in $(A \times B).$

Let $A = \{1, 2, 3, 4, 5\}$ and $B = \{2, 3, 6, 7\}$. Then the number of elements in $(A \times B) \cap (B \times A)$ is

If $A = \{1, 2, 4\}, B = \{2, 4, 5\}, C = \{2, 5\},$ then $(A - B) \times (B - C)$ is

If $A = \{2, 3, 5\}$ and $B = \{2, 5, 6\}$,then $(A - B) \times (A \cap B)$ is:

Let $n(A) = 3$ and $n(B) = 3$ (where $n(S)$ denotes the number of elements in set $S$). Then,the number of subsets of $(A \times B)$ having an odd number of elements is:

If $R$ is the set of all real numbers,what do the Cartesian products $R \times R$ and $R \times R \times R$ represent?