\textbf{148-} The degrees of vertices of a simple, connected graph are $a, b, c, 2, 2, 3, 3, 4, 5$. If the graph has $\frac{1}{5}$ equal to $(a+b+c)$, how many different cases does the set $\{a, b, c\}$ have?
\medskip
(4) $2$ \hfill (3) $3$ \hfill (2) $5$ \hfill (1) $4$
\medskip