Ans: C
Let $a$ and $d$ be the first term and the common difference of the arithmetic sequence. Then we have
Let $a$ and $d$ be the first term and the common difference of the arithmetic sequence. Then we have
$\left\{ \begin{array}{ll}
a+2d =18 & \ldots \unicode{x2460} \\
a+5d =-6 & \ldots \unicode{x2461}
\end{array}\right.$
$\unicode{x2461} – \unicode{x2460}$, we have
$\begin{array}{rcl}
3d & = & -24 \\
d & = & -8
\end{array}$
Therefore, the $2$nd term
$\begin{array}{cl}
= & a+d \\
= & (a+2d) – d \\
= & 18 – (-8) \\
= & 26
\end{array}$
