O'Reilly Incorporated makes and sells many consumer products. The firm's average contribution margin ratio is 25%. Management is considering adding a new product that will require an additional $18,000 per month of fixed expenses and will have variable expenses of $9.00 per unit. Required: a. Calculate the selling price that will be required for the new product if it is to have a contribution margin ratio equal to 25%. b. Calculate the number of units of the new product that would have to be sold if the new product is to increase the firm's monthly operating income by $12,000. Note: Do not round intermediate calculations. a. Selling price per unit b. Number of units