Jean-Pierre consumes only apples and bananas. He prefers more apples to less, but he gets tired of bananas. If he consumes fewer than 28 bananas per week, he thinks that one banana is a perfect substitute for one apple. But you would have to pay him one apple for each banana beyond 28 that he consumes. The indifference curve that passes through the consumption bundle with 31 apples and 40 bananas also pass through the bundle with X apples and 23 bananas, where X equals?