pb = 70 -0.0005qb(brand name) pp = 20-0.0002qp (private label). Marginal cost is a constant $10 per tire.quantities are measured in thousands per month and price refers to the wholesale price. marginal cost is a constant $10 per tire. american currently sells brand name tires at a wholesale price of $28.50 and private label tires for a price pf $17. Are these prices optimal for the firm?