I worked this problem, but I just want to check and make sure I did it correctly.
Given U = {15,16,17,18,19,20,21,22,23,24,25}
A = {16,18,20,22}
B = {17,19,20,23,24}
Find A'�¿B'. Finding A', then B' then find their intersection.
What did you get?
Don't know what "character encoding" your browser uses, but in Western-ISO8859-1, you can put
∩ as & c a p ;
∪ as & c u p ;
(do not type the intervening spaces)