Vox is a brick manufacturing company that uses process costing to determine the cost of the bricks they make. This example looks at two of the departments in the process of production: the crushing department, and the batching and mixing department.

The raw materials $($clay or shale$)$ are delivered, and then become the input to the first step of the brick$-$making process. In this step, the raw materials are crushed down into gravel$-$like small stones $($output$)$ by the crushing department. This substance becomes the input to the next process, which is the batching and mixing of the powder to create a brick body mix, which is then ground. The following costs have been calculated for each department this month:

Crushing:

Raw materials $($clay$)$ R$40,000$

Labour R$12,500$

Manufacturing overheads R$5,000$

$10,000$ units were produced in the crushing department with no wastage.

Batching and mixing:

Raw materials $($crushed clay$)?$

Labour R$16,400$

Overheads R$8,200$

$10,000$ units started in production, $7,000$ units completed, $3,000$ units in closing work in progress. The $3,000$ incomplete units were on average $40\%$ complete as regards to all conversion costs $($direct labour $+$ manufacturing overhead$).$ Calculate the cost per unit produced in the crushing department that is transferred to the batching and mixing department. Show all calculations.

Question $3$

Calculate the cost of completed units produced as well as the cost of work$-$in$-$progress in the batching and mixing department. Note: The degree of completion can be different for each cost component.

Question $4$

If there was a normal amount of spoilage worth R$6,900$ that occurred at the end of the crushing phase of this process, how would the cost per unit change? Provide an explanation