22. (15points) Marytreats goods and as perfect complements always combining 2 units of good x with one unit of good y. (1) Can Mary's preferences be represented by the utility function (,)=minimum{2,4}? If yes, why? If not, present a utility function for Mary.(2) Find Mary's optimal consumption choice when the prices and herincome are (1,1,1)=(1,4,18)and heroptimal consumption choice when the prices and herincome are (2,2,2)=(2,1,20). (3) Based on your answers for part (2), which of the two price-income combinations is preferred by Mary?