Standing Waves Questions

When a string is divided into three segments of length $l_1,l_2$ and $l_3$, the fundamental frequencies of these three segments are ${\nu }_1,{\nu }_2$ and ${\nu }_3$ respectively. The original fundamental frequency ($\nu$) of the string is:

If $n_1,n_2$ and $n_3$ are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency $n$ of the string is given by: