For most products, higher prices result in a decreased demand, whereas lower prices result in an increased demand. Let d : annual demand for a product in units p : price per unit Assume that a firm accepts the following price-demand relationship as being realistic: d:800-lOp wherep must be between $20 and $70. a. How many units can the firm sel1 at the $20 per-unit price? At the $70 per-unit price? b. What happens to annual units demanded for the product if the firm increases the per- unit price from $26 to $27? From $42 to $43? From $68 to $69? What is the sug- gested relationship between the per-unit price and annual demand for the product in units? c