Data Scientist Statistics & Math Interview Questions
Practice 455 real Statistics & Math interview questions for Data Scientist roles. From companies including Meta, Capital One, Google, Amazon, Uber.
"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."
Compare solar vs biomass paybacks and recommend
Compare two investments. Assume all energy prices/costs are per MWh and the selling price is $40 per MWh. Project A (Solar): initial investment = $12....
Compute p-values and adjust multiplicity
You test if a coin is fair after 20 flips and observe 17 heads. (a) Compute the exact two-sided p-value under a Binomial(20, 0.5) model. (b) Approxima...
Analyze omitted-variable bias in regression
Omitted-Variable Bias, Heteroscedasticity, and Remedies Setup - True data-generating process (DGP): Y = β0 + β1·Temp + β2·Occupancy + ε - Assumption...
Design cross-validation; explain bias–variance
Define cross-validation rigorously and compare k-fold, stratified k-fold, leave-one-out, nested CV, and time-series rolling/blocked CV. For a dataset ...
Define and compute surge pricing metrics
Surge Pricing Metrics, Formulas, and Causal Estimation You are evaluating surge pricing in a two-sided marketplace (customers place requests; drivers/...
Compute probability second largest is below 2/3
Order Statistic Probability: P(U_(2) < 2/3) Context You draw three independent samples U1, U2, U3 from Uniform(0, 1). Let U_(1) ≤ U_(2) ≤ U_(3) denote...
Differentiate x^x and analyze domain
Compute the derivative of f(x) = x^x for x > 0 using logarithmic differentiation. State precisely the domain where the derivative is real-valued. Eval...
Quantify launch decision with tests and guardrails
You will formalize the statistical decision rules for the Instagram button experiment described above. Given: baseline exploration rate (p0) = 0.15 pe...
Derive paying users over time with churn
Leaky-Bucket Model of Paying Users Context - Time is discrete by month t = 1, 2, ... - Each month t: - N new users start a free trial. - a (fracti...
Decide if subgroup increases imply overall increase
TikTok Time: Subgroup Increases vs Overall Average (Simpson's Paradox) You are analyzing average daily time spent on TikTok by gender (male, female) a...
Define and compute retention and churn precisely
Retention and Churn for a Transactional Consumer App Context: You are analyzing retention and churn for a transactional consumer app (e.g., food deliv...
Compute sample size and plan experiment
A/B Test Planning: Paywall Copy Change For New Signups Context You are planning an A/B test to evaluate a paywall copy change that targets new signups...
Compute posterior for accurate-but-rare classifier
Bayes' Theorem: Interpreting Screening Model Predictions Context You are evaluating a binary screening model that flags "bad" users in a population. T...
Analyze results and large p-values correctly
Experiment Analysis Plan: User-Level ITT with Robust Inference, Variance Reduction, Ratios, Skew, Non-Compliance, and Decision Framework Context You r...
Derive no-click probability and sketch implications
Click Probability Across Repeated Impressions Context: We show A impressions of the same item to a user. Unless otherwise stated, each impression is a...
Match Year-2 profit to Year-1
Target Profit Volume Across Two Years Context You sell only classic burgers. Year 1 has negligible fixed costs; Year 2 introduces new fixed costs. The...
Interpret p=0.10 rigorously
A/B Test on Monthly Churn: Inference, Power, and Testing Choices You ran a 28-day A/B test to reduce monthly churn among subscribers, randomizing 150,...
Decide launch with p=0.10 at alpha 0.05
A/B Test Decision: Frequentist, Conditional Power, Bayesian, and Risk-Mitigation Context You ran a 50/50 A/B test on 30‑day subscriber retention. The ...
Differentiate LDA and QDA; compute boundary
Binary Gaussian Classification: LDA vs QDA You are modeling a 2D binary Gaussian classifier with features (x, y): - Class 0: mean μ0 = (0, 0), covaria...
Choose tests for rare-event A/B analysis
A/B Test for Rare Weekly Cancellations — Planning, Testing, and Monitoring You are testing whether a product change affects weekly cancellation probab...