Question 468007
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi,
U = {10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}, 
A = {12, 14, 16, 18, 20}, A' = {10,11,13,15,17,19}
B = {11, 13, 14, 15, 18, 19, 20}, B' = {10,12,16,17}
                               A&#8242; &#8745; B' = {10,17}