Consider a hypothetical perfectly competitive market for identical lunch boxes supplied to Monash students. All firms have TC=200+\frac12q^2, and market demand is Q_D=600-10P. Firms face identical costs, and entry and exit are free in the long run. A permanent fixed licence fee raises cost to TC=450+\frac12q^2. Market demand remains Q_D=600-10P. After entry or exit has restored long-run equilibrium, how many firms operate?

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