If $aN = \{ ax:x \in N\} ,$ then the set $3N \cap 7N$ is .....$N$
$21$
$10$
$4$
None of these
If $A=\{1,2,3,4\}, B=\{3,4,5,6\}, C=\{5,6,7,8\}$ and $D=\{7,8,9,10\} ;$ find
$B \cup C \cup D$
If $A = \{x : x$ is a multiple of $4\}$ and $B = \{x : x$ is a multiple of $6\}$ then $A \cap B$ consists of all multiples of
If $A$ and $B$ are two sets, then $A \cup B = A \cap B$ iff
If $A, B$ and $C$ are three sets such that $A \cap B = A \cap C$ and $A \cup B = A \cup C$ then
If $X=\{a, b, c, d\}$ and $Y=\{f, b, d, g\},$ find
$X-Y$