Data Scientist Interview Questions

Showing 1–30 of 47 results

• BBarclaysEasy·Data Scientist
  Determine Worker Counts from Production Ratios

  This problem tests mathematical modeling and systems of linear equations by requiring the candidate to derive specific headcount requirements based on production demand and individual productivity constraints.

  Statistics & MathOnline AssessmentAlgebraSystems of EquationsOptimization
• Boston Consulting GroupEasy·Data Scientist
  Calculate Probability and Statistics for Dice Roll Outcomes

  This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Probability and Statistics for Dice Roll Outcomes states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Statistics & MathOnline Assessment
• Boston Consulting GroupEasy·Data Scientist
  Calculate Probability of Heads and Red Balls Drawing

  This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Probability of Heads and Red Balls Drawing states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Statistics & MathOnline Assessment
• Boston Consulting GroupMedium·Data Scientist
  Compute posterior and predictive coin probabilities

  This question evaluates Bayesian inference and probabilistic reasoning, focusing on posterior updating, posterior predictive probability, and the conditional expectation of a stopping time given observed outcomes.

  Statistics & MathOnline Assessment
• C3 AIMedium·Data Scientist
  Explain Training R-Squared After Adding a Random Feature

  Prove that ordinary training R-squared cannot decrease when adding a feature, while adjusted and test-set R-squared can.

  Statistics & MathOnline Assessment
• CVS HealthMedium·Data Scientist
  Compute A/B significance, CI, and power

  This question evaluates proficiency in statistical inference for A/B testing—specifically two-proportion z-tests, construction of confidence intervals with unpooled standard errors, sample-size and power calculations, and multiple-comparison correction via Bonferroni.

  Statistics & MathOnline Assessment
• Capital OneMedium·Data Scientist
  Compute and interpret 95% confidence intervals

  This question evaluates proficiency with confidence intervals, hypothesis testing for proportions and means, multiple-comparison adjustment (Bonferroni), and sample size calculations, including assessment of normal-approximation versus Wilson score methods.

  Statistics & MathOnline Assessment
• CCitibankMedium·Data Scientist
  Compute expected payoff of reroll dice game

  This question evaluates understanding of probability theory and expected-value computation in stopping-time processes, including conditioning and infinite-series reasoning, and also tests modeling of per-trial costs and break-even analysis.

  Statistics & MathOnline Assessment
• CCitibankMedium·Data Scientist
  Price options and bonds via binomial no-arbitrage

  This question evaluates competence in no-arbitrage pricing, risk-neutral valuation, early-exercise features of American versus European options, and short-rate tree bond valuation within the Statistics & Math domain.

  Statistics & MathOnline Assessment
• FRFive RingsHard·Data Scientist
  Solve coin probability and Bayesian inference problems

  This question evaluates probabilistic reasoning, stochastic-process intuition (pattern waiting times and runs), expected-value calculations, and Bayesian parameter estimation competency.

  Statistics & MathOnline Assessment
• Goldman SachsEasy·Data Scientist
  Bound the Rank of BA Given Rank of AB

  Determine the set of possible values for the rank of the matrix product BA given that A and B are 4x4 real matrices and rank(AB) = 2. This question tests fundamental linear algebra inequalities involving matrix ranks and nullities.

  Statistics & MathOnline AssessmentLinear AlgebraMatrix TheoryRank Inequalities
• Goldman SachsEasy·Data Scientist
  Compute the Arc Length of a Curve

  Tests single-variable calculus fundamentals, specifically calculating the derivative, setting up the standard arc length integral, and evaluating it using substitution.

  Statistics & MathOnline Assessmentcalculusintegrationgeometry
• Goldman SachsEasy·Data Scientist
  Expected Number of Runs in Coin Tosses

  Tests understanding of linearity of expectation and indicator random variables through counting consecutive runs in a sequence of coin tosses.

  Statistics & MathOnline Assessmentprobabilityexpected-valuecombinatorics
• Goldman SachsEasy·Data Scientist
  Infer BA When AB Is the Identity

  This question tests the understanding of matrix invertibility, the properties of the identity matrix, and the fundamental differences between square and non-square matrix multiplication.

  Statistics & MathOnline AssessmentLinear AlgebraMatricesRank
• Goldman SachsEasy·Data Scientist
  Integrate a Two-Sided Exponential Density

  This question tests the ability to integrate probability density functions (PDFs) over specified intervals, specifically handling the absolute value function in symmetric distributions.

  Statistics & MathOnline AssessmentCalculusProbabilityDistributions
• HHeadlandsMedium·Data Scientist
  t-Stat With an Added Orthogonal Regressor, Live Sharpe Check, and Absolute-Loss Estimator

  Solve three core quantitative problems covering OLS regression mechanics under orthogonal regressors, statistical significance of backtested Sharpe ratios in live deployment, and loss-function minimization for L1 error.

  Statistics & MathOnline AssessmentEconometricsSharpe RatioLinear Regression
• OptiverEasy·Data Scientist
  Compute probabilities and expectations in random processes

  This question evaluates proficiency in probability theory, combinatorics, and mathematical expectation through a series of rapid-fire brain-teasers. It tests the ability to set up clean probabilistic models, apply the right technique, and derive exact closed-form answers under time pressure — skills commonly assessed in quantitative and data science interviews.

  Statistics & MathOnline Assessment
• OptiverHard·Data Scientist
  Find next terms in sequences

  This question evaluates pattern recognition, numerical reasoning, and sequence-inference competency across arithmetic, fractional, and recurrence-style relationships, and falls under the Statistics & Math domain relevant for data scientist roles.

  Statistics & MathOnline Assessment
• OptiverHard·Data Scientist
  Solve probability and expectation problems

  This problem tests your ability to calculate expected stopping times in a discrete random walk and your understanding of conditional expectation and symmetry in probability.

  Statistics & MathOnline AssessmentProbabilityExpectationStochastic Processes
• Point72Hard·Data Scientist
  Price a coin-doubling game rationally

  This question evaluates understanding of probability distributions, divergent expected values, utility theory, and optimal betting strategies (Kelly staking) within the Statistics & Math domain for a Data Scientist role.

  Statistics & MathOnline Assessment
• RobloxHard·Data Scientist
  Apply Bayes' rule to compute posterior

  Evaluates understanding of Bayes’ rule and basic probability concepts—specifically computing a posterior probability P(A|B) and the marginal likelihood P(B) from a prior and likelihoods—in the Statistics & Math domain at a foundational-to-intermediate abstraction level.

  Statistics & MathOnline Assessment
• RobloxEasy·Data Scientist
  Compute A/B test sample size and Bayes posterior

  This question tests the ability to calculate required sample size for a frequentist A/B test using power analysis and to perform a Bayesian update for a Bernoulli process.

  Statistics & MathOnline AssessmentStatisticsA/B TestingBayesian Inference
• RobloxHard·Data Scientist
  Compute sample size and Bayes posterior

  This question evaluates understanding of statistical inference and probabilistic reasoning by combining a frequentist power/sample-size computation for a two-sided two-sample z-test with a basic Bayesian conditional probability calculation.

  Statistics & MathOnline Assessment
• SIG (Susquehanna)Easy·Data Scientist
  Calculate Expected Payoff from Two Dice

  This problem tests fundamental knowledge of probability, expected value, and partitioning sample spaces to calculate the average outcome of a stochastic process.

  Statistics & MathOnline AssessmentProbabilityExpected ValueStatistics
• SIG (Susquehanna)Easy·Data Scientist
  Compute Conditional Age Probability Among Cyclists

  This question tests the ability to interpret a contingency table and calculate conditional probabilities by narrowing the sample space to a specific sub-group.

  Statistics & MathOnline AssessmentProbabilityStatisticsContingency Tables
• SIG (Susquehanna)Medium·Data Scientist
  Compute ruin probability with bold betting

  This question evaluates understanding of probability theory and stochastic processes, focusing on ruin probabilities under a bold betting strategy with state-dependent wagers.

  Statistics & MathOnline Assessment
• SIG (Susquehanna)Easy·Data Scientist
  Compute stockout sufficiency probability

  This question evaluates understanding of discrete probability and binomial models for independent Bernoulli trials, testing the ability to compute the probability that a limited resource meets random demand.

  Statistics & MathOnline Assessment
• SIG (Susquehanna)Easy·Data Scientist
  Compute the Probability Two Bloom Intervals Overlap

  Calculate the probability that two independent events with different known durations overlap within a fixed time window using geometric probability.

  Statistics & MathOnline AssessmentProbabilityContinuous DistributionsGeometric Probability
• SIG (Susquehanna)Easy·Data Scientist
  Condition on a Chosen Rabbit Losing

  Calculate the conditional probability that a randomly selected rabbit is the least athletic of three rabbits given that it lost its benchmark race, using Bayes' theorem.

  Statistics & MathOnline AssessmentProbabilityBayes' TheoremConditional Probability
• SIG (Susquehanna)Easy·Data Scientist
  Count Cookie Flavor Combinations

  Calculate the number of distinct unordered combinations when selecting 5 cookies from 4 available flavors with replacement, and contrast this with the ordered outcome space.

  Statistics & MathOnline Assessmentcombinatoricsstars-and-barsprobability