Let  A = {n $$ \in $$ N: n is a 3-digit number}

       B = {9k + 2: k $$ \in $$ N}

and C = {9k + $$l$$: k $$ \in $$ N} for some $$l ( 0 < l < 9)$$

If the sum of all the elements of the set A $$ \cap $$ (B $$ \cup $$ C) is 274 $$ \times $$ 400, then $$l$$ is equal to ________.

Set A has m elements and set B has n elements. If the total number of subsets of A is 112 more than the total number of subsets of B, then the value of m.n is ______.

Let X = {n $$ \in $$ N : 1 $$ \le $$ n $$ \le $$ 50}. If
A = {n $$ \in $$ X: n is a multiple of 2} and
B = {n $$ \in $$ X: n is a multiple of 7}, then the number of elements in the smallest subset of X containing both A and B is ________.