Answer:
A^C = {2,3,5,6,10,12,14,15,17,18,20}
B^C = {1,3,5,6,9,11,15,16,18,20}
C^C = { 5,9,10,15,16,20}
Explanation:
The C means the complement or the items in the main set and not in the subset
Given U = {1,2,3,4,5,......18,19,20}
A^C = means the items in U that are not in A
A^C = {2,3,5,6,10,12,14,15,17,18,20}
B^C = means the items in U that are not in B
B^C = {1,3,5,6,9,11,15,16,18,20}
C^C = means the items in U that are not in C
C^C = { 5,9,10,15,16,20}