Problem: Given the set whose elements are zero and the even integers, positive and negative. Of the five operations applied to any pair of elements:
(1) addition
(2) subtraction
(3) multiplication
(4) division
(5) finding the arithmetic mean (average),
those operations that yield only elements of are:
Answer Choices:
A.
B. 1, 2, 3, 4
C.
D.
E.
Solution:
Addition, subtraction, and uultiplication with even integers always yield even integers.