A manufacturing firm produces three products: P, Q, and R. What is the total revenue generated from these products in a month? Statements: I: The firm sells Product P for $400, with production costs of $250. The firm sells Product Q for  $600,  with production costs of $400. The firm sells Product R for $800, with production costs of $600. In a month, the firm sells 300 units of P, 250 units of Q, and 200 units of R. II: The firm has an overhead cost of $20,000 per month that is allocated equally across all products. III: The total number of units sold for all products combined is 750, and the firm expects a 15% increase in sales next month.