Let  $S_1:$ The number of subsets of $\left\{a,b,\left\{a,b\right\}\right\}$ is 16.
$S_2:\{a,b\}\subset \{a,\{a,b\},c\}$
$S_3:$ For any finite set S, let $\left|S\right|$ denote the number of elements in S. The number of ordered pairs $(A,B)$  such that A and B are (not necessarily distinct) subsets of  $\{1,2,\mathrm{3.........},n\}$  that satisfy  $\left|A\right|.\left|B\right|=|A\cap B|.|A\cup B|$ then  $A\cup B=A$ or   $A\cup B=B$
The number of TRUE statements among the   $S_1,S_2,S_3$