$A-(A-B)$ is
$A \cup B$
$A \cap B$
$A \cap {B^c}$
${A^c} \cap B$
If $A=\{3,6,9,12,15,18,21\}, B=\{4,8,12,16,20\},$ $C=\{2,4,6,8,10,12,14,16\}, D=\{5,10,15,20\} ;$ find
$B-C$
Find the union of each of the following pairs of sets :
$X =\{1,3,5\} \quad Y =\{1,2,3\}$
If $\mathrm{R}$ is the set of real numbers and $\mathrm{Q}$ is the set of rational numbers, then what is $\mathrm{R - Q} ?$
If $A, B, C$ be three sets such that $A \cup B = A \cup C$ and $A \cap B = A \cap C$, then
If the sets $A$ and $B$ are defined as $A = \{ (x,\,y):y = {e^x},\,x \in R\} $; $B = \{ (x,\,y):y = x,\,x \in R\} ,$ then