Let $S = \{1,2,3,...,18,19,20\}$ be the universal set.
Let sets A and B be subsets of S, where:
Set $A = \{2,6,7,9,10,11,12,13,16,17,19,20\}$
Set $B = \{1,5,8,9,12,13,16,19\}$
Determine the following:
$n(A) = $
$n(\overline{A}) = $
$n(B) = $
$n(A \cap B) = $
$n(A \cup B) = $