Overlapping Sets & Venn Diagrams
Section: Statistics & ProbabilityBank code: STA-OVLGRE frequency: HighPro
1. Core Idea
When two groups overlap, simply adding their sizes double counts the members in both. The correction is the inclusion-exclusion principle:
Total in A or B = A + B - (both)
For questions with two attributes and a yes/no answer for each, a 2x2 table is usually faster and less error-prone than a Venn diagram.
The rest of this note is part of Pro
Must-know rules, three worked examples, the GRE traps, speed tricks and a self-check — plus every one of the 75 concept notes and all 8,390 questions.
Reading free? 25 notes are free, including every exam-strategy note.