If $A$ and $B$ are any two sets, then $A \cap (A \cup B)$ is equal to
$A$
$B$
${A^c}$
${B^c}$
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
$B-C$
$A-(A-B)$ is
If $A=\{3,5,7,9,11\}, B=\{7,9,11,13\}, C=\{11,13,15\}$ and $D=\{15,17\} ;$ find
$\left( {A \cup D} \right) \cap \left( {B \cup C} \right)$
Let $A$ and $B$ be two sets. Then
If $A$ and $B$ are disjoint, then $n(A \cup B)$ is equal to