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Probability and quant reasoning games
Free practice games for the probability, estimation and quick-reasoning questions found in trading and quant interview assessments. Each game has an untimed Learn mode that explains every answer and a timed Test mode that scores you.
What each game trains
Probability and expected value
Dice, coins, cards, conditional probability and random walks. Work out a probability or an expected value and pick the closest of five answers. A right answer scores +1, a wrong one −1 and a skip 0, so the game also trains knowing when to answer and when to move on. Every answer is computed exactly, and Zetapro's own tests check each formula against a simulation.
Number sequences
Find the rule behind a sequence and pick the next number from five options. Questions ramp from simple steps to recurrences, product chains and fraction cycles, and the wrong options come from rules that fit only part of the sequence. You can skip a question and come back to it.
Ranking likelihoods
Rank three outcomes from most to least likely, using tables, distribution charts and state graphs. Questions are built around the classic traps: a stricter event can't be more likely than a looser one, impossible events, variance versus mean, and near-ties only a point or two apart. Only the exact order scores.
Estimation intervals
Give a lower and an upper bound for a quantity: a count from a picture, a length against a scale bar, a quick statistic on a set of numbers, a probability or a mental calculation. A range that contains the answer scores lower ÷ upper, so a tight, correct range scores close to 1 and a miss scores 0. It trains calibration: ranges wide enough to be right and narrow enough to score.
Order-book arbitrage
A board of 6 to 8 cards for items and bundles, each quoting a price you can buy at and a price you can sell at. Find trades that leave every item flat and your cash positive. One card is mispriced: a direct cross, a bundle against its parts, or a ratio between two pack sizes. It trains reading quotes quickly and checking that positions net to zero.
Speed, attention and risk
Three short games. Number Box: combine four numbers with +, −, × and ÷, each used once, to hit a target. Code Compare: pick the exact copy of a code from near-misses, faster and faster. Balloon: pump for points or cash in before it pops, which tests how you take risk.
Ways to practice
- Learn is untimed. Every answer is explained straight away, followed by a review by topic.
- Test is timed and scored. Results go into your stats, with a trend for each game, your weakest topics, and the review of any past round.
- Quick play is a casual run on the same questions: three lives, combos for answers in a row, a speed bonus, and a clock that gets faster as you level up.
- A full practice run takes every game once, in order, with breaks between stages as long as you like. A closing report rates each game and lists your biggest point losses, such as ranges that are too narrow, each with what to practice.
- Leaderboards are optional: join with a nickname to compare scores this week and all time.
How the games help with trading interviews
The games practice skills that trading and quant interview assessments often test under time pressure: fast, accurate arithmetic, probability and expected value, spotting patterns, estimating with honest uncertainty, and noticing when prices don't add up.
Real assessments differ between firms and change over time, so treat these games as practice for the skills rather than a copy of any test. For arithmetic speed, pair them with Zetapro's Classic rounds, a Zetamac-style speed game, and 80 in 8, which has 80 multiple-choice questions in 8 minutes with decimals and fractions.
Zetapro is free and independent. It is not affiliated with or endorsed by any trading firm.