A firm with costs C(Q) = 1; 000 + 60Q + 0:1Q2 is able to price-discriminate between two groups of customers, with demands Q1 = 3; 000-2p, and Q2 = 350-0:5p respectively. How much does it sell to each group, and at what price? What would happen if it were forced to charge all its customers the same price?