please asnwer a b and c

Nora Incorporated sells a single product for $15. Variable costs include $6.15 for each unit plus a 8% sales commission. Fixed costs are $145,350 per month. Required: a. What is the contribution margin ratio? b. What is the break-even sales revenue? c. What sales revenue is needed to achieve a $113,220 per month profit? Complete this question by entering your answers in the tabs below. What is the contribution margin ratio