Which of the following sets is finite?

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 $m \times n$ is

If $A = \{x : x = \frac{n-1}{n+1}, n \in W\}$ and $\{n \leq 10\}$,point out the correct statement from the following:

If $A=\{1,2,3\}, B=\{2,3,4\}, C=\{1,3,4\}$ and $D=\{2,4,5\},$ then $(A \times B) \cap (C \times D) =$

$2n (A \setminus B) = n (B \setminus A)$ and $5n (A \cap B) = n (A) + 3n (B)$,where $P \setminus Q = P \cap Q^C$. If $n (A \cup B) \leq 10$,then the value of $\frac{n(A) \cdot n(B) \cdot n(A \cap B)}{8}$ is:

Of the members of three athletic teams in a school,$21$ are in the cricket team,$26$ are in the hockey team,and $29$ are in the football team. Among them,$14$ play hockey and cricket,$15$ play hockey and football,and $12$ play football and cricket. Eight play all the three games. The total number of members in the three athletic teams is: