Assume that Donald's preferences over good X and good Y are represented by the utility function 2 U(z,y) = *(2y + 1) and his total budget I 160.The price for X is Py = 10 and that for Y is py = 10. Then the optimal quantity for good Xis o One considers X and Y to be perfect complements. More specifically, one's preferences are represented by the following Leontief utility function U(x, y) = min(ax, y), where a > 0.