Use the following information to answer the given question.
\(\begin{array}{c|c} & ₦\\ \hline \text{Prime cost} & 4,000\\ \text{Factory overheads} & 6,000\\ \text{Stock on 1/1/09 work-in-progress} & 1,000\\ \text{Stock on 31/12/09 work-in-progress} & 2,000 \\ \text{Returns inwards} & 800 \\ \text{Sales} & 20,000\end{array}\)
Cost of production is