Answer:
a. Set is a well defined collection of elements which may be mathematical such as numbers, functions, e.g.
i. A universal set is a set which has elements or members of all related sets.
II. A null set is a set that doesn’t contain any values or elements.
iii. A subset is a set which is part of a given set.
iv. An equivalent set is a set that contains the same number of elements of another set.
v. Equal sets are sets that have equal number of elements.
vi. Finite sets are sets that have a countable number of elements.
vii. Infinite sets are endless sets.
Explanation: