Let A, B, and C be any three events defined on a sample space S. Let N (A), N (B), N (C), N (A ∩ B), N (A ∩ C), N (B ∩ C), and N (A ∩ B ∩ C) denote the numbers of outcomes in all the different intersections in which A, B, and C are involved. Use a Venn diagram to suggest a formula for N (A ∪ B ∪ C). sum N (A) + N (B) + N (C) and use the Venn diagram to identify the “adjustments” that need to be made to that sum before it can equal N (A ∪ B ∪ C).] As a precedent, note that N (A ∪ B) = N (A) + N (B) − N (A ∩ B). There, in the case of two events, subtracting N (A ∩ B) is the “adjustment.”