Perfect competition and equilibrium.
a. Put the demand and supply curves together (at the original productivity and wages). Helen assumes that she is in a perfectly competitive market. How many pies will she sell? At what price?
b. Draw the area of consumer surplus on your graph. Draw the area of producer surplus.
c. Calculate consumer surplus as the sum of the difference between the price and the marginal utility for each pie. Calculate producer surplus as the sum of the difference between price and marginal cost for each pie.