Overlapping Sets (GMAT Focus Course - Advanced Quantitative and Verbal Concepts)

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Basic Group Equations
- Total (Union) = Group A + Group B - Overlap (Intersection) + Neither
- Group X Only = Group X - Overlap (Intersection)
Three Group Equation for Overlapping Sets
- Total = G1 + G2 + G3 - Exactly Two Groups - 2(All Three) + None
Secondary Group Equation for Multiple Categories
- Total = Exactly One Category + Exactly Two Categories + All Three Categories
- Can be Extrapolated to Any Number of Characteristics
- Note for Savvy Shortcuts in Solving for Complex Group Word Problems

[@ashishsinha9035]

Thanks a lot for the excellent session ! I especially liked the way you solved the last question (about finding out none or exactly one) in one step. I was so far solving this kind of questions in 2 steps, first deriving neither and deriving exactly one. But my approach was onerous. However, I believe for this kind of question Venn Digram approach is the best. Formula is required only when instead of individual values of overlap of 2, combined value of overlap of exactly 2 is given.

[@Paddle_Shifter]

For the three group questions, how do you determine when to use each formula among the two provided?

[@someguy2972]

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