Drum Music Ltd. enjoys the exclusive copyright on music written and produced by a popular rock group. Marginal costs and average costs for production and distribution of music are stable at $10 per CD. The market demand for the rock group' CD is given by the following relation:

Q=5000-100P

a)Calculate Drum's output, price, and total profits at the profit-maximizing level, in the presence of copyright protection.

b)Following the expiration of copyright protection, the market becomes perfectly competitive. What output, price, and profit levels would then prevail?

c)Discuss the relationship between elasticity and market power, with reference to the differences between the market structures identified in part a) and part b).