If $A=\{1,2,3,4\}, B=\{3,4,5,6\}, C=\{5,6,7,8\}$ and $D=\{7,8,9,10\} ;$ find

$A \cup B \cup C$

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 $B \cap C$

If $X=\{a, b, c, d\}$ and $Y=\{f, b, d, g\},$ find

$X-Y$

If $X = \{ {4^n} – 3n – 1:n \in N\} $ and $Y = \{ 9(n – 1):n \in N\} ,$ then $X \cup Y$ = . . . . .

If $A, B$ and $C$ are any three sets, then $A – (B \cap C)$ is equal to