Suppose that a monopolist hires labor to produce its output in the competitive labor market. The market demand for the output isP = 100 - Q, where P is the unit price of output. The production function isQ = 2L, where Q is the output level, and L is the amount of labor used. If the labor supply function isPL = 20 + L, what is the equilibrium price of labor at the competitive equilibrium in the labor market?