State whether the following set is finite or infinite:
The set of animals living on the earth.

The set $A = \{ x : x \ne x \}$ represents:

If ${N_a} = \{an : n \in N\}$,then ${N_5} \cap {N_7} = $

Set $A$ has $m$ elements and Set $B$ has $n$ elements. If the total number of subsets of $A$ is $112$ more than the total number of subsets of $B$,then the value of $m \times n$ is

Find the union of each of the following pairs of sets:
$A = \{ x : x \text{ is a natural number and a multiple of } 3 \}$
$B = \{ x : x \text{ is a natural number less than } 6 \}$

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