CAPE Pure Mathematics Unit 1 · May/June 2010 · Paper 1 · Question Q26

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}