Robert only consumes X and Y, and his indifference curves have the usual convex shape. Consider the consumption bundles (3, 9), (6, 6), and (9, 3) (hint: they lie on a straight line). If Robert is indifferent between (3, 9) and (9, 3), then:
A) he prefers (3, 9) over (6, 6).
B) he prefers (9, 3) over (6, 6).
C) he prefers (6, 6) over both (3, 9) and (9, 3).
D) he prefers (6,6) over (3,9) but not over (9,3).

Question

Quizplus · Accepted Answer

Since (3,9) and (9,3) are on the same indifference curve and lie on a straight line with (6,6), it means that (6,6) is also on that indifference curve. Therefore, Robert is indifferent between (3,9), (6,6), and (9,3). However, since (6,6) is a balanced bundle where he gets an equal amount of X and Y, it is preferred over bundles where he gets more of one good and less of the other (i.e. (3,9) and (9,3)). Therefore, he prefers (6,6) over both (3,9) and (9,3).

Robert Only Consumes X and Y, and His Indifference Curves