1. A two-person economy consists of Ann and Bob. Both of them only consume x and y. Ann's utility over these two goods is UA(xA, yA) = xAy 2 A and Bob's utility is UB(xB, yB) = x 2 ByB. Initially, Ann is endowed with 9 units of x and zero units of y; Bob is endowed with 6 units of y and zero units of x. (a) Write Ann's marginal rate of substitution in terms of xA and yA and Bob's marginal rate of substitution in terms of xB and yB. (b) Derive the equation for the Pareto set (or contract curve).