Are the following pair of sets equal? Give reasons.
$A = \{ x : x \text{ is a letter in the word } \text{FOLLOW} \}$
$B = \{ y : y \text{ is a letter in the word } \text{WOLF} \}$

Examine whether the following statement is true or false:
$\{x : x \text{ is an even natural number less than } 6\} \subset \{x : x \text{ is a natural number which divides } 36\}$

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

In a city,no two persons have an identical set of teeth,and there is no person without a tooth. Also,no person has more than $32$ teeth. If we disregard the shape and size of the teeth and consider only the presence or absence of a tooth at each of the $32$ positions,then the maximum population of the city is:

In the following,state whether $A = B$ or not:
$A = \{2, 4, 6, 8, 10\}$; $B = \{x : x \text{ is a positive even integer and } x \le 10\}$

Find the union of each of the following pairs of sets:
$A = \{1, 2, 3\}, B = \varnothing$