Math help please!

1. A set is a collection of objects whose elements are well defines. Identify the statement that does not define a set a. The set of natural numbers greater than one and less than 10 b. The set of vowels in the alphabet c. The set of important people in your town d. The set of integers less than 5 2. Identify an empty set from the following: a. The set of integers, I = [1, 2, 3, 4,...} b. The set of days of the week i.e. {x| x = S, M, T, W, Th, F, S}. c. {x /x E N and x