$A$ die is thrown. Describe the event $A$: a number less than $7$. Find $A \cup B$ if $B$ is the event of getting a number $3$.

Let $A$ and $B$ be two sets in a universal set $U$. Then $A - B$ is equal to:

If $A = \{ x : x \text{ is a natural number} \}$,$B = \{ x : x \text{ is an even natural number} \}$,$C = \{ x : x \text{ is an odd natural number} \}$ and $D = \{ x : x \text{ is a prime number} \}$,find $B \cap C$.

Which Venn diagram represents the truth of the statement "No child is naughty"?
Where $U$ = Universal set of human beings,$C$ = Set of children,$N$ = Set of naughty persons.

$A$ die is thrown. Describe the following events: $A$: a number less than $7$,$B$: a number greater than $7$. Find $A \cap B$.

Let $A$ and $B$ be two sets such that $n(A) = 0.16$,$n(B) = 0.14$,and $n(A \cup B) = 0.25$. Then $n(A \cap B)$ is equal to: