Probability Online Assessment (OA) Practice
Penalty-scored, five-option probability questions that mirror trading-firm OAs.
Free account required to play.
Many trading firms screen with a timed probability online assessment: multiple-choice questions under penalty scoring, where a wrong answer costs you and skipping is sometimes the right call. It tests genuine probability judgement and time management, not just whether you know a formula.
The Probability OA simulator reproduces that format — five options per question, penalty scoring of +1 / 0 / −1, and roughly 90 seconds per question. Exam mode hides your results until the end (like the real assessment); Practice mode shows the worked solution after each question so you learn as you go. The question bank spans dice, coins, cards, Bayes, expected value, random walks, and more.
What it's modelled on
Optiver's ‘Beat the Odds’ probability assessment
This is built in the spirit of Optiver's 'Beat the Odds' online assessment — timed, penalty-scored probability questions covering odds, expected value, and conditional reasoning — the same style of early-round probability screen that firms like Citadel also use. Five options, +1 / 0 / −1 scoring, and a per-question timer, so guessing has negative expected value and time management matters.
What it trains
- Discrete and continuous probability, expected value, and Bayes' reasoning
- Decision-making under penalty scoring — when to answer and when to skip
- Time management across a timed, multi-question assessment
How it's scored
Penalty scoring: +1 for a correct answer, 0 for a skip, −1 for a wrong answer, with about 90 seconds per question. Free runs a fixed 5-question Easy taster; Premium sets the count, difficulty, and topic.
Related guides
Frequently asked questions
- What is a probability OA in a quant interview?
- It's a timed online assessment of multiple-choice probability questions, usually under penalty scoring so guessing is discouraged. Firms use it as an early filter, so practising the exact format — options, penalty, and per-question timer — matters as much as the underlying probability.
- How does penalty scoring work, and should I skip questions?
- A correct answer scores +1, a skip scores 0, and a wrong answer scores −1. That means blind guessing has negative expected value — if you can't narrow the options, skipping is often the higher-EV choice. Practising under penalty scoring trains that judgement.
- Is the Probability OA the same as Optiver's 'Beat the Odds'?
- It's built in the same spirit — timed, penalty-scored probability questions covering odds, expected value, and conditional reasoning. NeetQuant's Probability OA lets you practise that style of assessment with a large, varied question bank.