Ticktock Ltd makes clocks with a selling price of 50 per clock. Budgeted production and sales volume is 1,000 clocks per month. During September 1,000 clocks were made and 900 clocks were sold. There was no opening inventory. The variable cost per clock is 20. Fixed costs in September were, as budgeted, 6,000. Using marginal costing the contribution and profit for September would be calculated as