Statistics & Math interview questions

Showing 331–360 of 439 results

• Count Cookie Flavor CombinationsEasy

  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.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Count Grid Paths with No Three Equal MovesEasy

  Count lattice paths from `(0, 0)` to `(5, 5)` that never use three identical directions consecutively. The solution converts paths into alternating runs of length one or two, counts bounded compositions for equal and unequal run totals, and derives 84 valid paths.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Deduce Cat Counts from Conditional Truth RulesEasy

  Deduce the exact number of cats owned by three individuals based on conditional truth-telling rules, percentage relations, and average constraints.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Determine a Canoe Departure TimeEasy

  This problem tests algebraic modeling and systems of linear equations by requiring the candidate to derive the counts of different entities based on a total sum constraint.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Determine departure time from travel timesMedium

  This question evaluates a candidate's understanding of relative motion, time-distance-rate relationships, algebraic modeling, and quantitative reasoning. Commonly asked in technical interviews for Statistics & Math and Data Scientist roles, it assesses the practical application of setting up and manipulating equations from multi-step word problems rather than purely conceptual theory.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Determine knights and knaves rolesEasy

  This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Determine knights and knaves roles states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  SIG (Susquehanna)Data ScientistStatistics & MathTechnical Screen
• Expected Number of Same-Rank Pairs in a Hand Dealt Without ReplacementMedium

  An expectation question about dealing K cards without replacement from a deck of M ranks with N cards each, then counting the same-rank pairs in the hand. It tests linearity of expectation, probabilities when drawing without replacement, and how the definition of a pair changes the answer.

  SIG (Susquehanna)Quantitative TraderStatistics & MathOnline Assessment
• Expected Payoff of a Three N-Sided Dice Matching GameMedium

  An expected value question about rolling three fair N-sided dice, with different payoffs when all three match, exactly two match, or all differ. It tests counting the outcome classes correctly for a general number of faces and combining them into one expected payoff, including a variant where the all-different outcome costs money.

  SIG (Susquehanna)Quantitative TraderStatistics & MathOnline Assessment
• Find Expected Spins Until Two Regions AppearEasy

  This problem tests knowledge of expected value and geometric distributions by calculating the expected number of trials to observe two distinct outcomes from a discrete probability distribution.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Find a Green Triangle's Weight in a Balanced MobileEasy

  Solve a nested balanced-mobile puzzle and determine the green triangle's weight from a 160-pound total. The worked derivation uses an explicit equal-arm, massless-bar assumption, propagates whole-submobile weights upward, and explains why the left branch alone fixes the answer at 10 pounds.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Find probability of overlapping bloomsMedium

  This question evaluates understanding of probability theory, specifically reasoning about continuous uniform distributions, geometric probability, and the likelihood of overlap between random time intervals within a fixed horizon.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Find the Expected Number of Consecutive Chosen PairsEasy

  Calculate the expected number of consecutive pairs in a uniformly chosen subset of integers using indicator variables and linearity of expectation.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Find the Probability Two Muffins Are SufficientEasy

  This problem tests binomial probability distributions and the cumulative probability of independent discrete events.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Find the Success Probability of Bold BettingEasy

  Calculate the chance of reaching five tokens before ruin under a bold, state-dependent betting rule. The solution enumerates the transitions, sets absorbing boundaries, solves the four-state recurrence for win probability one-third, and obtains 15/77 from an initial fortune of two.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Infer posterior after losing pickEasy

  This question evaluates a candidate's understanding of conditional probability and posterior inference, assessing the ability to update probability estimates after observing that a chosen option did not occur.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Probability Limited Stock Covers Every Customer in a QueueMedium

  A binomial probability question about a queue of N customers who each choose one of two products, with only M units of one product left in stock. It asks for the probability that the stock is enough, or exactly enough, for every customer who wants it, testing distribution modeling and the efficient evaluation of tail sums.

  SIG (Susquehanna)Quantitative TraderStatistics & MathOnline Assessment
• Probability Two Randomly Started Flower Bloom Periods OverlapMedium

  A probability question about two flowers that start blooming on random days within a D-day window and stay in bloom for different lengths of time. It asks for the probability that both are in bloom together at some point, testing interval-overlap reasoning, exact counting, and discrete versus continuous modeling.

  SIG (Susquehanna)Quantitative TraderStatistics & MathOnline Assessment
• Probability You Picked the Strongest Cat Given Your Cat Lost the RaceMedium

  A conditional probability puzzle about three cats in a race with known winning probabilities. You cheer for a randomly chosen cat, learn whether it won or lost, and must find the probability that you picked the strongest or the weakest cat, testing Bayes' rule and the choice of conditioning event.

  SIG (Susquehanna)Quantitative TraderStatistics & MathOnline Assessment
• Probability of Reaching a Chip Target Under Bold BettingMedium

  A gambling probability question: starting with A chips and aiming for B, a player uses bold play, staking either all chips or just what is needed to reach the target, and wins each even-money round with probability p. It asks for the probability of reaching the target before going broke, testing recursive state analysis.

  SIG (Susquehanna)Quantitative TraderStatistics & MathOnline Assessment
• Resolve Two Knights-and-Knaves StatementsEasy

  This question tests logical deduction and systematic case analysis under binary truth constraints.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Solve Barn Animal Counts from Total LegsEasy

  Tests setting up and solving a system of linear equations from verbal constraints using substitution to determine integer entity counts.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Solve animals-and-legs countEasy

  This question evaluates a candidate's ability to translate a word problem into a system of linear equations and perform basic algebraic manipulation and arithmetic to determine unknown quantities.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Solve relative-truth cat puzzleMedium

  This question evaluates logical deduction, constraint satisfaction, and quantitative manipulation of percentages and averages within a relative truth/lie framework, and is categorized under Statistics & Math and discrete logic puzzles.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Use Bayes for factory identificationEasy

  This question evaluates understanding of Bayesian inference and conditional probability by asking for the posterior probability that two observed black widgets originated from a specific factory.

  SIG (Susquehanna)Data ScientistStatistics & MathOnline Assessment
• Estimate laptops in an officeMedium

  This question evaluates back-of-the-envelope estimation skills, quantitative reasoning, and the ability to state and justify assumptions when modeling real-world counts like devices.

  SamsungData ScientistStatistics & MathHR Screen
• Perform no-calculator math accurately and fastMedium

  This question evaluates mental arithmetic, rapid estimation, numerical bounds, and familiarity with exponentials and square-root approximations within the Statistics & Math category for a Data Scientist role.

  ShopifyData ScientistStatistics & MathTechnical Screen
• Analyze OLS After Duplicating Every ObservationMedium

  This question tests your understanding of OLS coefficient estimation and standard error calculations under the scenario of duplicate data observations.

  SnapchatData ScientistStatistics & MathTechnical Screen
• Diagnose Violations of Linear Regression AssumptionsMedium

  Tests a candidate's systematic understanding of ordinary least squares (OLS) regression assumptions, distinguishing how specific violations compromise unbiased point estimation, standard error inference, and predictive accuracy.

  SnapchatData ScientistStatistics & MathTechnical Screen
• Explain median vs mean for L1/L2Medium

  This question evaluates understanding of central tendency and loss functions—specifically the roles of median and mean under L1 (absolute) and L2 (squared) norms—and the geometric extension of these concepts to two-dimensional data.

  SnapchatSoftware EngineerStatistics & MathTechnical Screen
• How to Update Bayesian Model for Concept Drift?Medium

  How to Update Bayesian Model for Concept Drift? evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  SnapchatData ScientistStatistics & MathOnsite