Gibson Manufacturing uses normal costing for its job$-$costing system, which has two direct$-$cost categories $($direct materials and direct manufacturing labour$)$ and one manufacturing overhead cost pool$).$ The following information is obtained for $2007$:

Total manufacturing costs, R$8000000$

Manufacturing overhead applied, R$3600000($applied at the rate of $200\%$ of direct manufacturing labour costs$)$

Work$-$in$-$Process inventory on $1$ January, R$320000$

Cost of goods manufactured, R$7920000$

Required:

$5\mathrm{.}1$ Use the information in the first two bullet points to calculate:

a$.$ Direct manufacturing labour costs in $2007$

b$.$ Cost of direct materials used in $2007$

$5\mathrm{.}2$ Calculate the ending work$-$in$-$process inventory on $31$ December $2007.$