Statistics & Math Interview Questions
Practice 482 real Statistics & Math interview questions for 2026 — Statistics & Math interview questions gathered from actual interviews, with detailed solutions to guide your interview preparation. Covers companies like Meta, Capital One, Google, Amazon, and Optiver and roles such as Data Scientist, Quant/Trader, ML researcher, and Data Analyst. This collection is distinctive because problems range from applied inference
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
"The solution quality is insane. It covers approach, edge cases, time complexity, follow-ups. Nothing else comes close."
"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Determine roles from B's accusation
Knights and Knaves: Single Statement Inference You meet two islanders, A and B. Each person is either a knight (always tells the truth) or a knave (al...
How to derive correlation from variances
You have two random variables X and Y. You are given: - Var(X + Y) - Var(X) 1) Is the correlation Corr(X, Y) identifiable from only these two quantiti...
Determine Probability of Both Children Being Boys
Scenario A classic conditional-probability brain-teaser used in data science screens to test probabilistic reasoning and the discipline of stating ass...
Explain Central Limit Theorem's Importance in A/B Testing
Statistics Knowledge Check: CLT, A/B Testing, and Confidence Interval Context You are in a data science interview. Answer the following about the Cent...
Calculate Ad Insertion Statistics for Two Methods
Scenario Evaluating two ad-insertion strategies in a 100-post feed. - Option A (independent placement): Each post independently becomes an ad with pro...
Explain Type I and Type II Errors in Hypothesis Testing
Statistics Fundamentals: Type I vs Type II Errors and A/B Test Trade-offs Task You are discussing hypothesis testing in the context of a past modeling...
Compute posterior fake probability using Bayes' rule
A platform runs an automated detector to flag fake accounts. - Prior probability an account is fake: \(P(F)=0.02\). - True positive rate (sensitivity)...
Estimate bots and CI from DAU spike
Mixture Spike and Mean-Difference Inference for Daily Comments Context A product has DAU (daily active users) = 2,000,000. On day T, total comments in...
Compute sample size and test duration
You will run a two-arm A/B test on a signup funnel. Given: baseline conversion p0 = 4.0%; you care about detecting a 10% relative uplift (p1 = 4.4%); ...
Graph WTP vs content and explain cap
Willingness-to-Pay (WTP) vs. Content Quantity Context Assume the number of available shows is a nonnegative quantity S (S ≥ 0). A customer's maximum w...
Estimate population singletons from a 10% log
A daily search log has one row per query string. You draw a 10% simple random sample of rows without replacement. Define a “unique query” (singleton) ...
Estimate unbiased ad scores with many reviewers
You have 1,000 ads and 100 reviewers; each reviewer rates 100 ads on a 1–10 scale with incomplete overlap. Specify a mixed-effects model to estimate l...
Model comment count distribution and validate assumptions
You observe daily comment counts per post on a large social app are highly skewed with many zeros. a) Choose an appropriate discrete model among Poiss...
Diagnose a non-significant experiment outcome
A/B Test Interpretation, Power, and Decision-Making Under Asymmetric Loss Context You ran a two-sample A/B test on a primary mean metric (two-sided t-...
Compute power and cost-aware thresholds
You are evaluating a new ACH velocity+shared-device block rule. Assumptions - Volume: 1,000,000 ACH credits/month. - Baseline fraud prevalence: 0.15% ...
Characterize and compare transfer-count distributions over time
P2P Transfer Counts in First 30 Days: Distribution, Summaries, and Evolution Context: For a new user cohort, define X as each user’s number of peer-to...
Compare first-score vs all-scores estimators
You have two candidate estimators for survey quality based on the score column over 2025-08-26 to 2025-09-01: - E_first: For each user×survey pair, ta...
Compute p-values, power, and adjust errors
Statistics Interview Task (Onsite) You are evaluating a product experiment and related analytics questions. Answer precisely, showing calculations and...
Diagnose and fix linear regression violations
Given a linear model y = Xβ + ε on 10,000 observations: (a) State all Gauss–Markov assumptions and which are needed for BLUE vs inference. (b) Show wh...
Apply Bayes theorem with conjugate priors
A website’s true daily purchase conversion p is unknown. Prior: p ~ Beta(2, 8). Day 1: 10 purchases out of 120 visits; Day 2: 18 purchases out of 150 ...