4. Suppose that the short-run labor demand curve is LD 100 10w, where w is the wage rate. Moreover, both unskilled natives and unskilled immigrants both supply their labor inelastically, i.e. the labor supply curve is Ls = Q, where is the labor force in the labor market. Assume that unskilled natives and unskilled immigrants are perfect substitutes for the firms. Initially, there is 10 natives and 0 immigrants. (a) What is the equilibrium wage rate initially?(3 marks) (b) Suppose the number of immigrants increases from zero to 10. What is the new short-run equilibrium wage rate?(3 marks)