If ${N_a} = [an:n \in N\} ,$ then ${N_5} \cap {N_7} = $
${N_7}$
$N$
${N_{35}}$
${N_5}$
If $X=\{a, b, c, d\}$ and $Y=\{f, b, d, g\},$ find
$X \cap Y$
Let $A$ and $B$ be two sets. Then
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
$B-A$
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
$D-B$
Find the union of each of the following pairs of sets :
$A = \{ x:x$ is a natural number and multiple of $3\} $
$B = \{ x:x$ is a natural number less than $6\} $