From the previous question, we know $n^2-n+1$ will be the weight of the MST with $n>2$
Evidently, only $V_1$ and $V_2$ are connected, and no other vertex $V_i$ is connected to $V_{i+1}$
We can wisely use the above equation. For a path between $V_5$ and $V_6$, vertices more than 6 are redundant, since weight only increases for a larger $i$ of any vertex $V_i$ here.
We only need an MST upto 6 vertices. Path from $V_5$ to $V_6$ ill be included in it. It's weight will be $n^2-n+1$
=> $36-6+1$
=> $31$