Understanding the Inclusion-Exclusion Principle (Set Union Formula for Two-Set Functions)

Fascinated by my vague attempt at performing the Practice GMAT (Score: 11/15), I found myself diving deeper into the Set Union Formula (Two-Set Function) and it’s revelance to the Venn Diagram. What’s important to note is that this formula helps when you need to compare two or more data sets from groups that overlap with each other. But I discovered that you’ll need to know three important things:

  • Know how many are in the group individually
  • How many are in both groups
  • Want to find how many are in either group or both

Formula: | A ∪ B | = | A | + | B | – | A ∩ B |
A represents Data Set A
B represents Data Set B
A υ B represents the total of both data sets
A n B represents the overlapping data sets

Learning Source: https://www.youtube.com/watch?v=YlKDp03Kg68


Comments

One response to “Understanding the Inclusion-Exclusion Principle (Set Union Formula for Two-Set Functions)”

  1. Robert Reinhardt Avatar

    There are also three set formulas which are more advanced. This will be the formula I will be focusing on next.

    | A ∪ B ∪ C | = | A | + | B | + | C | – | A ∩ B | – | A ∩ C | – | B ∩ C | + | A ∩ B ∩ C |

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