Evaluate $\begin{vmatrix}2 & 0 & -1 \\ 3 & 0 & 4 \\ 5 & 1 & 6\end{vmatrix}$.

Explanation

1. 01

   Column 2 has two zeros, so expand along it: only $a_{32} = 1$ contributes.

2. 02

   Its sign is $(-1)^{3 + 2} = -1$ and its minor is $\begin{vmatrix} 2 & -1 \\ 3 & 4 \end{vmatrix} = 11$.

3. 03

   So the determinant is $-1 \times 1 \times 11 = -11$.