Let $A = \{ (x,\,y):y = {e^x},\,x \in R\} $, $B = \{ (x,\,y):y = {e^{ - x}},\,x \in R\} .$ Then
$A \cap B = \phi $
$A \cap B \ne \phi $
$A \cup B = {R^2}$
None of these
Find the union of each of the following pairs of sets :
$A = \{ x:x$ is a natural number and multiple of $3\} $
$B = \{ x:x$ is a natural number less than $6\} $
If $A=\{3,5,7,9,11\}, B=\{7,9,11,13\}, C=\{11,13,15\}$ and $D=\{15,17\} ;$ find
$A \cap C$
State whether each of the following statement is true or false. Justify you answer.
$\{a, e, i, o, u\}$ and $\{a, b, c, d\}$ are disjoint sets.
If $A =$ [$x:x$ is a multiple of $3$] and $B =$ [$x:x$ is a multiple of $5$], then $A -B$ is ($\bar A$ means complement of $A$)
If $A=\{1,2,3,4\}, B=\{3,4,5,6\}, C=\{5,6,7,8\}$ and $D=\{7,8,9,10\} ;$ find
$A \cup C$