P3.1 Demand and Supply Curves. The following relations describe monthly demand and supply conditions in the metropolitan area for recyclable aluminum QD = 317,500 - 10,000P (Demand) QS = 2,500 + 7,500P, (Supply) where Q is quantity measured in pounds of scrap aluminum and P is price in cents. Complete the following table: Price (1) Quantity Supplied (2) Quantity Demanded (3) Surplus (+) or Shortage (-) (4) = (2) - (3) 15 16 17 18 19 20