d某甲所面對之名目利率與實質利率分別為何？（4%)

a. If De Beers charges the monopoly price, what is the monopoly price? How large is the individual consumer surplus that each buyer experiences at this monopoly price? Calculate total consumer surplus by summing (lie individual consumer surpluses. How large is producer surplus? (10%) Suppose that upstart Russian and Asian producers enter the market and the market becomes perfectly competitive.