CAPE Pure Mathematics Unit 2 · May/June 2018 · Paper 1 · Question Q37

If \mathbf{M} = \begin{pmatrix} 1 & 1 & 4 \\ 3 & 2 & -1 \\ 6 & 0 & 5 \end{pmatrix}, then the co-factor of the element 3 in \mathbf{M} above may be written as

1. (A)\begin{vmatrix} 1 & 4 \\ 0 & 5 \end{vmatrix}
2. (B)-\begin{vmatrix} 1 & 4 \\ 0 & 5 \end{vmatrix}
3. (C)\begin{vmatrix} 2 & -1 \\ 0 & 1 \end{vmatrix}
4. (D)-\begin{vmatrix} 2 & -1 \\ 0 & 1 \end{vmatrix}