Chapter 2 - Set Theory - 2.4 Set Operations and Venn Diagrams with Three Sets - Exercise Set 2.4 - Page 92: 43

(A∩B∩C)'= {1,2,3,4,5,7,8,9,10,11,12,13}

(A∩B∩C)' The set (A∩B∩C), represents the all the common regions of the set A and B and C. and set (A∩B∩C)' represents all the regions that does not belongs to (A∩B∩C)'. From the given Venn diagram we can conclude that the region I, II, III, IV, VI, VII, VIII belongs to set (A∩B∩C)'. The elements of these regions are 1,2,3,4,5,7,8,9,10,11,12,13. So, (A∩B∩C)'= {1,2,3,4,5,7,8,9,10,11,12,13}