good is excludable if: a. it is Wi-Fi or a similar service. b. people who do not pay cannot be easily prevented from using the good. c. one person's use of the good does not reduce the ability of another person to use the same good. d. people who do not pay can be easily prevented from using the good.

The correct answer is:

people who do not pay can be easily prevented from using the good. (d)

Explanation:

Excludable goods or services are those to which the consumer cannot have access unless payment of some form is made. By contrast, a non-excludable good or service is one to which the consumer cannot be prevented from using even without payment. Excludable goods can be further divided into rivalrous and non-rivalrous.

A rivalrous excludable good or service is one in which usage by a consumer or usage by one party prevents or reduces significantly, its use by another consumer or party examples are goods such as clothes, food, cars etc, while non-rivalrous excludable goods/services include tv subscriptions, cinemas, etc.

b. a single paragraph.

a paragraph is a series of sentences that are organized and make sense, and are all related to a single topic . almost every piece of writing you do that is longer than a few sentences should be organized into paragraphs. this is because paragraphs show a reader where the subdivisions of an essay begin and end, and thus the reader see the organization of the essay into subjects in order to be able to understand its main points.

there's 11 people for the 1st position. then, no matter who gets it, there's only 10 left for the second, and then 9 left for the third. 11 x 10 x 9 = 990.   the answer is there are 990 different ways the positions can be filled by these applicants