CAPE Pure Mathematics Unit 1 · May/June 2014 · Paper 1 · Question Q27

Given that \mathbf{a} = \begin{pmatrix} -3 \\ 7 \end{pmatrix} and \mathbf{b} = \begin{pmatrix} 2 \\ -1 \end{pmatrix}, then |3\mathbf{a} + 2\mathbf{b}| is equal to

1. (A)\sqrt{386}
2. (B)\sqrt{336}
3. (C)\sqrt{554}
4. (D)\sqrt{504}