Hi this is very urgent as i'm about to sit an exam, I couldn't sleep
due to anxiety and I am a poor student and the questions being
answered (15 min time limit per question) would save my life. Please
let me know if you need web space details to upload images.

1. Assume that the gold-mining industry is perfectly competitive. All
firms have upward sloping short-run marginal cost curves and U-shaped
short-run average cost curves. Suppose that an increase in the demand
for jewellery causes an increase in the demand for gold. Use diagrams
to show what happens in the short-run to the gold market and to each
existing gold mine. If the demand for gold remains high, what will
happen to price over time? Is it possible that the new long-run
equilibrium price will be above the original equilibrium price?

2. Suppose there are 100 Sushi bars operating competitively in Sydney.
Each sushi bar has the usual short-run marginal cost and average cost
curves. The market demand curve for sushi slopes downwards and the
market is initially in long-run competitive equilibrium. Use graphs
for the entire market and for an individual sushi bar that is still
operating to illustrate what happens when the city decides to restrict
the number of sushi bars to 80. If the city council decides to charge
the 80 sushi bars a license fee, what is the highest licence fee they
can charge in order to ensure that all 80 sushi bars remain in
operation? Show your answer graphically.

3. A large number of companies produce CD's in a perfectly competitive
industry. All companies have upward sloping short-run marginal cost
curves and U-shaped short-run average cost curves. Suppose that the
government introduces a CD tax. Illustrate what happens to the price
and profita of an individual CD firm in the short-run. What happens to
the number of CD firms in the long-run? What about industry supply?
What about long-run profits?