Pear Ltd makes leather iPhone cases that sell for $$40$ each. For the coming year, management expects fixed costs to total $$70000$ and variable costs to be $$12$ per unit.Show all your workings.Required:$($a$)$ Calculate the contribution margin ratio.$($b$)$ Calculate breakeven sales in dollars and units.$($c$)$ Calculate the margin of safety ratio $(\%)$ assuming sales are $$125,000.($d$)$ Calculate the sales required to earn profit of $$140,000$