If $n(A) = 3$, $n(B) = 6$ and $A \subseteq B$. Then the number of elements in $A \cup B$ is equal to

State whether each of the following statement is true or false. Justify you answer.

$\{2,3,4,5\}$ and $\{3,6\}$ are disjoint sets.

Let $V =\{a, e, i, o, u\}$ and $B =\{a, i, k, u\} .$ Find $V – B$ and $B – V$

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

Find the intersection of each pair of sets :

$X=\{1,3,5\} Y=\{1,2,3\}$