Consider the system of linear equations



Let $S_1$ be the set of all $a \in \mathbb{R}$ for which the system is inconsistent and $S_2$ be the set of all $a \in \mathbb{R}$ for which the system has infinitely many solutions. If $n(S_1)$ and $n(S_2)$ denote the number of elements in $S_1$ and $S_2$ respectively, then