Suppose that the variable production overhead cost of a product is as follows:

4 hours at $3 = $12per unit.

During the period, 5,000 units of the product were made. The labour worked 6,050 hours of which 90 hours were recorded as idle time. The Variable overhead cost was $20,000.

Calculate the following variances:

1. The variable overhead total variance
2. The Variable production overhead Expenditure Variance
3. The Variable production overhead Efficiency Variance.