Jim's preferences over cookies (x) and other goods (y) are given by U(x, y) = xy with

Question:

Jim's preferences over cookies (x) and other goods (y) are given by U(x, y) = xy with associated marginal utility functions MUx = y. and MUy = x. His income is $20.
a) Find Jim's demand schedule for x when price of y is Py = $1.
b) Illustrate graphically the change in consumer surplus when the price of x increases from $1 to $2.