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:
Bundle (31 , 40) has 40 bananas. So 40 - 28 = 12 bananas These 12 banana give the consumer negative utility which will be balance one for one apple. So we have to need 12 apple to balance it. So the final utility of apples and banana is 28 + (31 - 12) = 28 + 19 = 43 In second bundle (X , 23) has 23 bananas. We need to get the same utility 43. Which we will get from 43 - 23 = 20 apples. So X equal to 23.
