If the sales volume increases by 20 % , then selling expenses increase by 15%. What proportion of selling expenses was fixed at the initial sales volume, and at the final sales volume? TE2 At a sales level of 10 000 units per month, the manufacturing overhead per unit is R3.30/unit. If the sales level increases by 4 000 units, the manufacturing overhead per unit falls to R2.70. What is the variable manufacturing overhead per unit? TE3 At a sales level of 10 000 units per month, the manufacturing overhead per unit is R4.00/unit. The next month the price of all manufacturing costs increase by 5%. If the sales level increases by 4 000 units, the manufacturing overhead per unit falls to R3.48. What is the variable manufacturing overhead per unit? TE4 The total manufacturing costs incurred during a year was R460 000, which comprises both variable and fixed costs in a ratio of 3:2 respectively, at a production level of 80 000 units. If a production level of 100 000 units is reached, a discount of 5% is available on all variable costs. What will the total manufacturing costs be at a production level of 120 000 units? TES The total manufacturing cost per unit was R10 at a production level of 90 000 units. If the production level increases to 111 000, total manufacturing costs will increase by 7%. What is the variable manufacturing cost per unit.