Hi, there-- THE PROBLEM: Find the difference between the number of elements in the union and the intersection of the following sets: M = {2, 4, 6, 8, 10, 12} and N = {1, 3, 5, 7, 9, 11} A SOLUTION: The union of two sets M and N is a set containing all elements present in set M or in set N or in both. M union N is {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}. There are 12 elements in the union. The intersection od two sets M an N is the set containing all the elements of M that also belong to B. (i.e. the elements they have in common) M intersection N is { }, the empty set. There are zero elements. The difference between the number of elements in the union and the intersection is 12. Hope this helps! Feel free to email if you have any questions about the solution. Good luck with your math, Mrs. F math.in.the.vortex@gmail.com