The demand and supply curves for T-shirts in Tourist town, U.S.A., are given by the following equations:

Q = 24,000 – 500P

Q = 6,000 – 1,000P

Where P is measured in dollars and Q is the number of T-shirts sold per year.

a. Find the equilibrium price and quantity algebraically.

b. If tourists decide they do not really like T-shirts that much, which of the following might be the new demand curve?

Q =21,000 – 500P

Q =27,000 – 500P

Find the equilibrium price and quantity after the shift of the demand curve.

c. If, instead, two new stores that sell T-shirts open up in town, which of the following might be the new supply curve?

Q = 4,000 + 1,000P

Q = 9,000 + 1,000P

Find the equilibrium price and quantity after the shift of the supply curve.