Jim's utility function is U(x, y) = xy. Jerry's utility function is U(x, y) = 1,000xy + 2,000. Tammy's utility function is U(x, y) = xy(1 - xy). Oral's utility function is U(x,y)= -1/(10+2xy).Marjoe's utility function is U(x, y) = x(y + 1,000). Pat's utility function is U(x, y) = 0.5xy - 10,000. Billy's utility function is U(x, y) = x/y . Francis's utility function is U(x, y) = -xy.
a. Who has the same preferences as Jim?
b. Who has the same indifference curves as Jim?
c. Explain why the answers to (a) and (b) differ.