WAEC Further Mathematics 2016 Paper

Concept:Matrix multiplication is performed by multiplying the rows of the first matrix with the columns of the second matrix.Explanation:Given $P=\begin{pmatrix}1&2\\5&1\end{pmatrix}$ and $Q=\begin{pmatrix}0&1\\1&3\end{pmatrix}$, we need to find $PQ$.For the element in the first row and first column: $(1)(0) + (2)(1) = 0 + 2 = 2$.For the element in the first row and second column: $(1)(1) + (2)(3) = 1 + 6 = 7$.For the element in the second row and first column: $(5)(0) + (1)(1) = 0 + 1 = 1$.For the element in the second row and second column: $(5)(1) + (1)(3) = 5 + 3 = 8$.Thus, $PQ = \begin{pmatrix}2&7\\1&8\end{pmatrix}$.Answer:The correct option is C: $\begin{pmatrix}2&7\\1&8\end{pmatrix}$.