Toby is indifferent between the bundles (9, 3) and (5, 5). When Toby is at (9, 3), he would be willing to give up one unit of y if he were to receive two units of x. If Toby is at (5, 5), he would be willing to give up four units of x if he were to receive two units of y.
Give two possible utility functions for Toby for goods x and y. Hint: draw a graph.