A country's labour market is characterized by the following labour demand and supply equations: LD = 96 - 3W and LS = W + 20, where W is the hourly wage.

a) Determine the incidence of a 10% tax on wages. Justify mathematically the distribution of this incidence.

b) Graph the equilibrium before and after tax.

c) What is the tax revenue and the deadweight loss of the tax?

d) Assume that the utility function of each worker between leisure (L) and his level of income from work (Y) takes the following form: U = 6 ln (L) + 4 ln (Y). How many hours does each worker work before and after wage tax? Interpret the result economically.