Question

b. which of the following describes the set of moving books? a. it is well defined. it is possible to list all of the moving books in the world. b. it is not well defined. there is no clear meaning of moving. c. it is not well defined. although there is a clear meaning of books, it is not possible to tell whether a thing is a book. d. it is well defined. for a given book, it is possible to tell whether it is moving. e. it is not well defined. there is no clear meaning of books. f. it is well defined. for a given thing, it is possible to tell whether it is a book.

Explanation:

A set is well - defined if for any object, we can clearly determine if it belongs to the set. For the set of “moving books”, the term “moving” is not clearly defined (e.g., moving at what speed, in what way? ). Option B states “It is not well defined. There is no clear meaning of'moving'.”, which correctly identifies the issue with the set's definition. Option A is wrong as we can't list all moving books doesn't relate to well - definedness. Option C is wrong as “books” is a clear concept. Option D is wrong as “moving” is not clear. Option E is about “books” being well - defined, not relevant to “moving books”.

Answer:

B. It is not well defined. There is no clear meaning of "moving."