The annual fixed costs for a small to medium plant are $100 000, and the variable costs are $140 000 at 70% capacity with net sales of $280 000. The selling price per unit is $40.

a)Calculate the break-even point in units of production and as a % of rated capacity with the aid of the break-even chart

b)Calculate the % return on investment and the payback period when the plant operates at full capacity