Jack receives 30 utils from one apple, 45 utils from two apples, and 55 utils from three apples. It follows that the marginal utility of the third apple is utils and that Jack's utility rises as his declines.

10

Total

Marginal

Explanation:

Marginal utility is the change in utility that occurs from consuming one extra unit of a good.

Marginal utitiy = 55 utils - 45 utils = 10 utils

Total utility is the utility derived from consuming a good or service.

When :

1. Total utility is 45 , marginal utility is 15

2. total utility is 55, marginal utility is 10

This shows that as total utility increases, marginal utility falls.

I hope my answer helps you

answer; no individual buyer or seller has any significant impact on the market price;