If the sets $A$ and $B$ are defined as $A = \{ (x,\,y):y = {1 \over x},\,0 \ne x \in R\} $ $B = \{ (x,y):y =  – x,x \in R\} $, then

If $A = \{1, 2, 3, 4, 5\}, B = \{2, 4, 6\}, C = \{3, 4, 6\},$ then $(A \cup B) \cap C$ is

Find the union of each of the following pairs of sets :

$A = \{ x:x$ is a natural number and $1\, < \,x\, \le \,6\} $

$B = \{ x:x$ is a natural number and $6\, < \,x\, < \,10\} $

Find the union of each of the following pairs of sets :

$A=\{1,2,3\}, B=\varnothing$

Show that $A \cup B=A \cap B$ implies $A=B$.