1) a) Given a pure exchange economy of 2 individuals (1, 2) and two private goods (X, Y) and no externalities; what is the Pareto efficiency condition? b) Given the pure exchange economy of 2 individuals (1, 2), and two private goods (X, Y), but where the consumption of x2 by person 2 enters the utility function of person 1; what is the Pareto efficiency condition? c) Fully explain the logic behind the efficiency condition in part (b). d) Fully explain the difference between the conditions in part (a) and part