WTL Ltd produces a stylish yet affordable handbag that sells for R30 per unit. Variable costs to manufacture and sell are R16 per unit. Fixed costs and expenses are budgeted at a total of R 54600 per year. Required: 3.1 Discuss the concept 'contribution margin.' 3.2 Calculate the break-even value in Rands. 3.3 Calculate the net income to be expected on sales of R240 000 . 3.4 Calculate the sales revenue required to produce net income of R7 000 . 3.5 If fixed costs were to be increased by R 25760 , calculate the increase in sales revenue that would be required to cover the increase in fixed costs. (4) 3.6 If the selling price is decreased by 20%, what percentage increase in the number of units sold is necessary to offset this decrease in selling price