Chapter 2 - Set Theory - 2.3 Venn Diagrams and Set Operations - Exercise Set 2.3 - Page 81: 13

A' = {21,22,23,24.......}

U = {1,2,3,4.....} A = {1,2,3,4,5....20} The set A' contains the elements that are not present in the set A. The elements of set A i.e.1,2,3,4,5....20 must not be present in set A. The elements of A' are 21,22,23,24..... Therefore A' = {21,22,23,24.......}