The sixth term of an arithmetic series is 12. The sum of the first 16 terms of the series is $S_n$ and $S_{16}=152$. Find the first term and common difference of the series.

A second arithmetic series has first term $-4$ and common difference $\frac{1}{2}$. The sum of the first $n$ terms of this series is $T_n$. Find the value of $n$ such that $T_n=S_n$, where $n>0$.