15) A market is defined as A) a physical place where people buy only goods. B) a physical place where people buy both goods and services. C) a store where people buy physical goods. D) any arrangement that brings buyers and sellers together. E) a place where one good is bartered for another.

D) any arrangement that brings buyers and sellers together.

Explanation:

In earlier times before now a market has a specific way of defining it. But due to recent advancement in technology, it can be described or defined to be any arrangement that brings buyers and sellers together.

The power of online presence totally altered the initial marker definitions the world know as any physical place where these buyers and sellers meet to do their tradings or businesses or a place where goods are bartered for another. Therefore any arrangement, be it via mail, sms, codes, online stores, video meetings etc are all forms of market places.

answer/// product differentiation;

answer: marginal utility of the fourth brownie is 0.

explanation: marginal utility is the addtional utility gained from the consumption of one more unit of a good. it is given by,

so, marginal utility at the 4th unit will be given by

since, the values are not given here, you can simply find marginal utility at fourth unit by subtracting total utility at 3rd unit from total utility at 4th unit.