Data Scientist Statistics & Math Interview Questions
Practice 471 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 Normal vs Poisson; test dispersion and approximate tails
You collect n=200 independent minute-level event counts with sample mean x̄=14.5 and sample variance s²=16.2. 1) Under a Poisson(λ) model, derive the ...
Compute sample size and test duration correctly
Powering Two Online Experiments: Sample Size, Duration, and Design Defenses You are designing experiments to improve a friend-accept rate metric in a ...
Explain p-value and choose correct test
Technical Screen: P-values and Robust Two-Sample/Paired Tests Context: You are a data scientist evaluating healthcare interventions. Answer in clear, ...
Compute probability second largest is below 2/3
This question evaluates understanding of order statistics, uniform probability distributions, and probabilistic reasoning, specifically the ability to...
Diagnose and interpret regression assumptions
This question evaluates proficiency in regression diagnostics and model selection for count outcomes, including OLS assumption checks, log-transformat...
Derive and validate DID for staggered rollout
Causal Effect of a Staggered Adoption Policy Across EU Regions You cannot randomize. An intervention is rolled out at different dates across EU region...
Analyze HT vs HH stopping-time probabilities
Coin-Flip Stopping Game: HT vs HH You repeatedly flip a coin until either the pattern HT appears (Player A wins) or the pattern HH appears (Player B w...
Measure rider incentive causal ROI
Rider Incentive Targeting: Causal Incrementality, ROI, and Spillovers Context: You plan a rider‑side incentive (e.g., “20% off up to $10”) targeted by...
Model session times and comments with exponential/Poisson
Session Duration Memoryless Assumption and Poisson Comment Counts Setup - We model user session end times with a constant hazard (memoryless) over tim...
Compute optimal stopping in a die-rolling game
Optimal stopping with a fair die (3-roll horizon) You observe outcomes of fair six-sided die rolls (faces 1–6) and may stop after any roll to take the...
Design an A/B test; choose Z vs T
A/B Test on a Signup Funnel: Sample Size, Test Choice, Sequential Design, and Causal Plan Context You are planning a two-variant A/B test on a signup ...
Validate DID and IV assumptions rigorously
Causal Inference and IV: DID, TWFE, Staggered Adoption, Clustering, and 2SLS Context: You are analyzing the causal effect of a reminder on an outcome ...
Optimize thresholds under fraud costs
Cost-sensitive Thresholding for Fraud (ATO) Classifier Context You are evaluating a binary classifier for account takeover (ATO) fraud on a large vali...
Compute P(Bag B | red) via Bayes
Bayes' Rule: Posterior Probability of the Chosen Bag Setup - There are three bags containing red (r) and green (g) balls: - Bag A: 4 r, 6 g (10 tota...
Compute expectations and test fairness for coin flips
You are analyzing repeated flips of a (possibly unfair) coin. Setup Let the probability of Heads be \(p\) (unknown in general). Assume flips are indep...
Derive the Optimal Bid in a Two-Bidder Second-Price Auction
Derive the Optimal Bid in a Two-Bidder Second-Price Auction Two risk-neutral bidders compete for one item in a sealed-bid second-price auction. Your p...
Compute expected counters after color elimination
Compute expected counters after color elimination Problem You have a bag with 30 counters: 10 red, 10 yellow, and 10 blue. You draw counters uniformly...
Fake Accounts [AE]
Evaluates probability, classification metrics, and feature engineering for fake-account detection. Strong answers apply Bayes' rule with rate-weighted...
Calculate Expected Day for First Selection in Sampling
Expected Day of First Selection in Daily Sampling There are 1,000 people. Each day, 10 distinct names are selected uniformly at random. Day counting s...
Assess Fundamental Statistics Knowledge in Data-Science Interviews
Fundamental Statistics for a Data Science Interview You are given several standard statistics tasks commonly used in a data-science technical screen. ...