Chapter 2 - Set Theory - 2.4 Set Operations and Venn Diagrams with Three Sets - Exercise Set 2.4 - Page 92: 37

(AUB)'= {12,13}

The set (AUB)', represents the all the elements of the universal set U which are not present in AUB From the given Venn diagram we can conclude that the regions VII and VIII are not represent the set (AUB). So the regions VII and VIII belongs to (AUB)'. The element of these regions are 12,13 So, (AUB)'= {12,13}