If two sets $A$ and $B$ have $99$ elements in common, then the number of elements common to the sets $A \times B$ and $B \times A$ is equal to
$2^{99}$
$(99)^2$
$100$
$18$
If the set $A$ has $3$ elements and the set $B=\{3,4,5\},$ then find the number of elements in $( A \times B ).$
If $P,Q$ and $R$ are subsets of a set $A$, then $R × (P^c \cup Q^c)^c =$
If $A$ and $B$ are two sets, then $A × B = B × A$ iff
Let $A = \{1, 2, 3, 4, 5\}; B = \{2, 3, 6, 7\}$. Then the number of elements in $(A × B) \cap (B × A)$ is
If $G =\{7,8\}$ and $H =\{5,4,2\},$ find $G \times H$ and $H \times G$.