How to use:
- Choose Set A, B, C, or D and a difficulty, then press Start for a 24-question, 15-minute session.
- Each answer is final; the next question appears immediately and you cannot go back.
- Keyboard shortcuts A–D and 1–4 work during the test.
- Each set is a separate fixed parallel form at each difficulty. Retaking the same set and difficulty repeats the same questions in a shuffled order; switch sets for another parallel form.
Question types:
- Base Rates & Conditional Probability: update probabilities when you learn new information and keep the direction of a condition straight.
- Chance & Independence: combine independent events, complements, repeated trials, and draws without replacement.
- Expected Outcomes & Intuition: compare expected values and recognize common probability traps involving streaks, conjunctions, sample size, and host information.
Difficulty:
- Easy: direct proportions, one-step probability rules, and basic intuition checks.
- Medium: two-step conditional reasoning, repeated-event calculations, and classic probability traps.
- Hard: Bayes-style updates, binomial or without-replacement reasoning, and multi-outcome expectations.
- Super Hard: multiple evidence sources, compound conditional paths, and denser probability calculations.
- Mixed Difficulty: each skill includes 2 Easy, 2 Medium, 2 Hard, and 2 Super Hard questions.
Scoring: each correct answer is worth 1 point. The performance label is a practice band based on this test only; it is not a percentile or standardized norm. Only completed or timed-out sessions are saved to history. Ending a test early discards the current run.