If $A \cap B = B$, then
$A \subset B$
$B \subset A$
$A = \phi $
$B = \phi $
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
$C-B$
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
$D-A$
If $X=\{a, b, c, d\}$ and $Y=\{f, b, d, g\},$ find
$Y-X$
If the sets $A$ and $B$ are defined as $A = \{ (x,\,y):y = {1 \over x},\,0 \ne x \in R\} $ $B = \{ (x,y):y = - x,x \in R\} $, then
If $X=\{a, b, c, d\}$ and $Y=\{f, b, d, g\},$ find
$X-Y$