Which of the following are sets? Justify our answer. (i) The collection of all even integers. (ii) The collection of questions in this Chapter.

Solution:

(i) The collection of all even integers can be considered as well-defined collection.

Since an integer which belongs to this collection can be found by anyone.

As a result, this collection can be considered a set.

(ii) The collection of questions in this Chapter can be considered as well-defined collection.

Since a question which belongs to this chapter can be found by anyone.

As a result, this collection can be considered a set.