{x: x is an integer neither positive nor negative} is   1. a countably infinite set. 2. an uncountable set. 3. an empty set. 4. a finite but not empty set.

Determine whether each of the sets described below is well-defined or NOT well-defined. -The set of even integers. -The set of easy problems in the exam. -The set of beautiful buildings in the city of Makati -The set of best foods in the University cafeteria -The set of all integers larger than π

write a word description of the set {1,3,5,7,9} The set of _________ less than ________.

Express the set using the roster method. {x|XEN and 30 ≤x≤90} Choose the correct answer below. OA. Ø O B. (30, 31, 32, 33, ..., 90} O C. {..., 27, 28, 29, 91, 92, 93, ...} O D. 31, 32, 33, 34, .... 90}