If $A$ and $B$ are disjoint, then $n(A \cup B)$ is equal to
If $A$ and $B$ are two sets, then $A \cup B = A \cap B$ iff
If $A=\{1,2,3,4\}, B=\{3,4,5,6\}, C=\{5,6,7,8\}$ and $D=\{7,8,9,10\} ;$ find
$B \cup C$
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\} $
If $A$ and $B$ are not disjoint sets, then $n(A \cup B)$ is equal to