probability Interview Questions
30 interview questions in our bank cover probability, most of them Coding & Leetcode-style Questions. They average 3.2/5 difficulty — medium — and each one was reported by a candidate after a real interview. Companies known to ask about probability: Optiver, Citadel, LinkedIn, Akuna Capital, OpenAI, and 15 more.
Practice these on the problems board →Companies that ask about probability
Question mix
- Coding & Leetcode-style Questions18
- ML Fundamentals & Algorithms12
Difficulty
- 2/5 — easy5
- 3/5 — medium14
- 4/5 — hard11
Questions tagged probability
Math Reasoning: Stopping Time / Las Vegas Algorithm
4/5Examine a sophisticated probability and stochastic reasoning challenge frequently asked in OpenAI technical interviews, focusing on optimizing randomized algorithms through strategic timeout designs. This exercise evaluates your mastery of mathematical bounds, expected value calculations, and restart strategies to minimize completion times for probabilistic tasks under uncertainty. It tests theoretical reasoning rather than raw programming skill. The complete analytical breakdown and expert solutions require a paid subscription.
Coding & Leetcode-style QuestionsOpenAIQR Statistics / Domain Knowledge Oral
4/5This rigorous interview evaluation from Two Sigma focuses on advanced mathematical reasoning and probability theory. Designed as an oral whiteboard session, it tests your ability to fluently derive concepts related to stochastic processes, regression analysis, and expected values. Interviewers look for deep theoretical comprehension rather than superficial memorization. Prepare yourself thoroughly for this challenging quantitative tier by accessing our complete study materials and expert guidance through a subscription.
ML Fundamentals & AlgorithmsTwo SigmaBeat the Odds — Probability Test (Optiver)
4/5This high-pressure quantitative screening challenge, widely reported during recruitment at Optiver, tests rapid mental math, probabilistic reasoning, and expected value estimation through a rapid-fire sequence of multiple-choice questions under strict time limits. It evaluates a candidate's numerical agility, risk management instincts, and estimation speed when facing statistical uncertainties. Unlock the complete practice test environment and expert solution strategies with a paid subscription.
ML Fundamentals & AlgorithmsOptiverEQR Alpha-Factor Research Deep-Dive + LLM Inference Stability
4/5This advanced technical assessment, reported from Citadel quantitative research rounds, dives deep into predictive alpha factor validation and the practical stability challenges of deploying large language models under inference noise. Candidates must demonstrate rigorous statistical intuition regarding look-ahead bias, information coefficient thresholds, and overfitting prevention, followed by live coding scenarios. It serves as a comprehensive test for quantitative machine learning engineering roles. Access to the full research case study questions and expert-crafted answers requires a subscription.
ML Fundamentals & AlgorithmsCitadelQuant OA Math / Probability Multiple-Choice Bank
3/5Prepare for technical screenings at Goldman Sachs with this curated bank of multiple-choice and numeric estimation questions focusing on core mathematics, calculus, probability, and statistical concepts. This challenge evaluates your analytical agility, problem-solving speed, and proficiency in fundamental quantitative methods under timed conditions. Access the full problem set and complete model solutions with a subscription.
ML Fundamentals & AlgorithmsGoldman SachsML Breadth Orals — Linear / Logistic / Random Forest / Optimizers
3/5This Amazon Applied Scientist technical screening evaluates core machine learning knowledge through a rigorous conceptual discussion covering classical algorithms, regression foundations, loss functions, and optimization dynamics. Interviewees must explain underlying statistical assumptions, differentiate between gradient descent variants, and reason through feature selection methods in tree-based ensembles. Preparing for this round ensures readiness for deep theoretical follow-ups often posed by hiring managers. Unlocking the complete guide with expert answers requires a paid subscription.
ML Fundamentals & AlgorithmsAmazonQR Technical Round — Brainteasers & Estimation
3/5This quantitative research technical round from Optiver evaluates candidate aptitude through a blend of probability puzzles, statistical reasoning, and rapid estimation techniques. Interviewers look for structured mathematical intuition and logical problem-solving under verbal constraints. To access the detailed question list, strategic approaches, and expert model answers, a paid subscription is necessary.
ML Fundamentals & AlgorithmsOptiverTrading Betting Game (EV / Market-Making)
4/5Encountered as a core quantitative trading interview module at Optiver, this live probability and market-making simulation tests your rapid decision-making under uncertainty. Candidates start with a fixed bankroll and must continually calibrate risk, stake amounts, and pricing odds across various stochastic sub-games involving random outcomes. Interviewers assess your mental math agility, probabilistic reasoning, and strategic adaptability under pressure over raw cumulative profit. Explore the complete problem mechanics, strategic frameworks, and expert guidance by securing a subscription.
ML Fundamentals & AlgorithmsOptiverStratified Sampling from Class-Bucketed Data
2/5This machine learning fundamentals problem, frequently asked in interviews at LinkedIn, focuses on implementing a custom sampling technique for class-bucketed data. The exercise tests your understanding of probability distributions by requiring a sampler that ensures a uniform probability across different classes, avoiding the common pitfall of biasing toward larger categories. Access to the comprehensive problem breakdown, underlying statistical principles, and complete code solution requires a subscription.
ML Fundamentals & AlgorithmsLinkedInBattery Cell Quality Statistical Case
3/5Tackle a rigorous manufacturing data analysis scenario modeled after real-world Tesla engineering evaluations. This case study tests your statistical reasoning and experiment design skills by asking you to analyze pass-fail inspection data across multiple randomized hardware categories to determine the superior batch. You will explore appropriate hypothesis testing methods, account for variance, and justify your analytical approach using robust statistical principles. Elevate your analytical expertise by unlocking the complete problem breakdown and professional model solution with our premium subscription.
ML Fundamentals & AlgorithmsTeslaModel Risk Orals: VaR and Monte Carlo Convergence
4/5Prepare for a rigorous Capital One risk validation interview with this deep dive into quantitative finance orals. The discussion focuses on nuanced concepts including Value at Risk behavior across directional positions, convergence criteria for Monte Carlo simulation paths, and comprehensive backtesting methodologies. Interviewers heavily grade your precision in financial terminology and theoretical foundations. Gain access to the full question breakdown and ideal expert responses with a subscription.
ML Fundamentals & AlgorithmsCapital OneLikelihood / Event-Ordering Test
2/5Featured in recent Optiver quantitative assessments, this timed evaluation presents candidates with data tables and charts, asking them to rapidly rank multiple scenarios based on their relative likelihoods. The format tests quick statistical intuition, risk assessment, and data interpretation under tight time constraints rather than heavy mathematical derivations. It provides a realistic preview of modern algorithmic trading screening modules designed to gauge analytical agility. Unlock the complete test overview and expert preparation guide with a subscription.
ML Fundamentals & AlgorithmsOptiverBeat the Odds — Probability Test (Optiver)
4/5Speed, accuracy, and sharp mental arithmetic are essential for conquering quantitative screening assessments widely known from Optiver hiring pipelines. This challenge tests your ability to rapidly compute expected values and navigate complex probability scenarios under strict time constraints where mistakes carry penalties. Success relies on quick estimation techniques and sound mathematical reasoning rather than exhaustive calculations. Standing out in this high-pressure environment requires rigorous practice with timed mental math exercises. Accessing the full test simulator, strategy breakdowns, and model answers requires an active subscription.
ML Fundamentals & AlgorithmsOptiverQR Video OA: Advanced Math and Reasoning
4/5This video-based quantitative assessment, reported at Akuna Capital, evaluates candidates on advanced mathematical reasoning, probability, calculus, and linear algebra through a series of timed verbal explanations. Interviewees must articulate complex concepts clearly while solving intricate brain teasers, such as grid-based infection spread dynamics. Performing well on this format requires both rigorous technical knowledge and the ability to communicate sophisticated ideas succinctly. Access the full question overview and expert answers with a subscription.
Coding & Leetcode-style QuestionsAkuna CapitalCorrelation Range + Box-Muller Sampling
4/5This quantitative interview prompt, sourced from Citadel, features two classic probability and statistics brainteasers often posed to financial engineering candidates. The first part explores the mathematical boundaries of correlation coefficients among three interdependent random variables, while the second focuses on transforming uniform random variates into a standard normal distribution using transformation algorithms. This challenge evaluates advanced statistical reasoning and mathematical intuition. Unlock the full derivations and detailed solutions by securing a subscription.
Coding & Leetcode-style QuestionsCitadelCommuter Coupon Conditional Probability
3/5This data science evaluation, sourced from reported Lyft screening interviews, tests core statistical reasoning and probability theory within a practical business framework. Candidates must analyze conditional probabilities connected to promotional coupon usage for commuter rides to compute marginal likelihoods and derive posterior distributions. The assessment typically begins with introductory database and data manipulation warm-ups before transitioning into this probability puzzle. To view the comprehensive breakdown, mathematical derivations, and verified code solutions, please subscribe to our platform.
Coding & Leetcode-style QuestionsLyftCard Counting Game
2/5Explore probability and simulation concepts through a card game scenario reported during technical interviews at Talroo. This puzzle challenges you to determine the expected number of draws required to encounter specific target cards within a standard randomized deck. It evaluates your fundamental understanding of probability distributions and algorithmic counting techniques. To view the complete problem statement along with the optimal coded solution, a paid subscription is required.
Coding & Leetcode-style QuestionsTalrooQuant Probability and Statistics Orals
3/5Prepare for quantitative finance interviews with this JPMorgan oral statistics and probability challenge covering infinite nested radicals, combinatorics involving coupled pairs, and game-theoretic expected values. This evaluation tests your mathematical intuition, quick mental agility, and rigorous statistical reasoning under interview pressure. Access the complete set of oral questions and expert-crafted model solutions with a paid subscription.
Coding & Leetcode-style QuestionsJPMorganSimulate the Monty Hall Problem
2/5This engaging Thumbtack interview problem asks you to write a simulation of a famous probability paradox involving three doors, a host, and a prize. You will model both switching and non-switching strategies over numerous trials to empirically calculate success rates and demonstrate statistical reasoning. The complete challenge specifications, simulation guidelines, and reference solution require a subscription.
Coding & Leetcode-style QuestionsThumbtackObstacle Course Run Analytics (Personal Best, Best-of-Bests, Monte Carlo)
4/5In this Headway interview challenge, you will build an analytics pipeline for an obstacle course timing application to process runner metrics and historical data. The task tests your debugging skills and ability to compute personal records, aggregate statistics, and probabilistic outcomes from incomplete runs. You will need to write clean, maintainable object-oriented code to handle edge cases in performance tracking. Unlock the full challenge details and the comprehensive model solution by subscribing today.
Coding & Leetcode-style QuestionsHeadwayProbability of Rolling a 1 First
3/5This reported interview question from Agoda challenges candidates to evaluate stochastic processes and probability theory using simulation techniques. You will work with two dice possessing different face counts, repeatedly rolling them until a specific target value appears. The core task involves estimating both the likelihood of a designated die hitting the target first and the average duration of the game. It tests your grasp of random sampling, statistical convergence, and iterative modeling. The complete problem statement, comprehensive test cases, and a verified model solution require a subscription.
Coding & Leetcode-style QuestionsAgodaUniform Sampler from a Biased Coin
3/5This LinkedIn interview question explores probability and simulation by asking you to build a fair random number generator using an unfair coin with an unknown bias. Candidates must design an algorithm that achieves uniform probability over a larger range while analyzing expected call counts and worst-case performance bounds. It tests advanced probability theory and bit manipulation techniques. To unlock the full problem breakdown and expert solution, a subscription is required.
Coding & Leetcode-style QuestionsLinkedInTrading OA — Probability Quickfire Closed Forms
3/5Sharpen your quantitative reasoning with this rapid-fire probability and expected value challenge reported from Citadel quantitative assessment processes. This set of questions explores combinatorial distributions, randomized shuffling outcomes, and uniform spatial separations, requiring sharp mathematical intuition and closed-form derivations under strict time constraints. It is an excellent test of fundamental stochastic concepts for quantitative roles. To review the complete question set and detailed mathematical solutions, a subscription is required.
Coding & Leetcode-style QuestionsCitadelWeighted Sampling from a Probability Distribution
3/5This LinkedIn coding interview question focuses on building an efficient weighted random sampler given an array of probabilities. You will need to design a class structure that handles initialization and sampling efficiently while addressing edge cases involving unnormalized weights. Access the full problem details and expert solution by securing a paid subscription.
Coding & Leetcode-style QuestionsLinkedInWeighted Sampling from Score Distribution
3/5This Pinterest coding challenge asks you to implement a weighted sampling mechanism. Given a collection of strings, each associated with an arbitrary real-valued score, the task is to select a single string such that its probability of selection is directly proportional to a derived, normalized version of its score. The problem specifically emphasizes the importance of addressing numerical stability issues that arise when dealing with a wide range of input scores, potentially involving very large, very small, or negative values. It tests your understanding of probability distributions and robust numerical computation. The full problem and model solution require a subscription.
Coding & Leetcode-style QuestionsPinterestWeighted Random Sampling with Insert - Delete
4/5Reported as a Citadel interview challenge, this problem asks you to maintain a dynamic collection of weighted items supporting fast insertions, deletions, and probabilistic random draws proportional to item weights. This task tests advanced data structure design, specifically utilizing prefix sum trees to achieve logarithmic time complexity across all operations. Mastering this requires deep familiarity with cumulative frequency tracking and binary indexing. Unlock the full problem description and reference solution with a subscription.
Coding & Leetcode-style QuestionsCitadelApproximate Pi Using Monte Carlo (Quarter Circle)
2/5Explore probabilistic numerical methods through this Veeva Systems interview challenge that asks you to estimate mathematical constants using randomized coordinates within a bounded geometric area. This exercise tests your proficiency in applying statistical sampling techniques and geometric formulas to compute floating-point approximations efficiently. To view the complete problem statement, underlying mathematical principles, and clean reference implementation, please unlock your account with a paid subscription.
Coding & Leetcode-style QuestionsVeeva SystemsData Manipulation and NLP with Bayesian Methods
3/5This Block interview question explores data processing and natural language analysis through probabilistic modeling. You will work on tokenizing textual input to compute word frequency distributions and apply statistical methods to estimate token likelihoods. The challenge tests your data manipulation skills, algorithmic efficiency, and ability to extract meaningful linguistic insights from unstructured inputs. The complete problem description and model implementation are available exclusively to subscribers.
Coding & Leetcode-style QuestionsBlockTrader Fair-Bet Probability and Number Sequences
3/5Sharpen your quantitative reasoning and rapid estimation skills with this financial assessment module frequently utilized by Akuna Capital during quantitative candidate evaluations. The evaluation measures your ability to quickly compute fair bet probabilities, perform mental calculations under severe time constraints, and recognize mathematical sequence patterns. Success depends on accuracy and speed when handling probabilistic risk scenarios without relying on lengthy derivations. Unlock the complete set of practice drills, advanced calculation strategies, and verified solutions by purchasing a subscription.
Coding & Leetcode-style QuestionsAkuna CapitalProbability of a Dice Roll Sum
3/5This Belvedere Trading interview question challenges you to compute the likelihood of obtaining a specific aggregate outcome when throwing standard multi-sided dice multiple times. It evaluates your grasp of probability theory, combinatorics, and dynamic programming approaches for counting valid outcomes. To view the full problem statement and expert model solution, a subscription is required.
Coding & Leetcode-style QuestionsBelvedere Trading
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probability interview FAQ
- How many probability interview questions are there?
- 30 reported questions, mostly Coding & Leetcode-style Questions.
- Which companies ask probability questions?
- Optiver (5), Citadel (4), LinkedIn (3), Akuna Capital (2), OpenAI (1), Two Sigma (1), Goldman Sachs (1), Amazon (1).
- How hard are probability questions?
- They average 3.2 out of 5: 5 at 2/5, 14 at 3/5, 11 at 4/5.