Module · Data Analysis
Chapter 27: Probability
Data Analysis
4 topics
🎯 1 practice questions
What this chapter covers
The 4 topics below make up Probability on the GRE. Click any topic to open its notes, examples and practice test.
Study material & tests
📚 Study this chapter
Notes, worked examples and hint-guided practice for every topic.
Start learning →
🎯 Topic tests
8 auto-graded questions per topic, pulled from the question bank.
Practice by topic →
📝 Chapter test
25 fresh mixed-difficulty questions, timed, with full solutions.
Take chapter test →
Formula Reference Sheet
This chapter
Core probability
| Basic probability | P(E) = favourable outcomes / total equally-likely outcomes |
|---|---|
| Range of a probability | 0 ≤ P(E) ≤ 1 |
| Complement | P(not E) = 1 − P(E) |
| Independent "and" | P(A and B) = P(A) × P(B) |
Combining events
| General "or" | P(A or B) = P(A) + P(B) − P(A and B) |
|---|---|
| Mutually exclusive "or" | P(A or B) = P(A) + P(B) (no overlap) |
| Dependent "and" | P(A then B) = P(A) × P(B given A) |
| "At least one" | P(at least one) = 1 − P(none) |
GRE reference
🖩 Graphing Calculator