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."
Calculate A/B sample size, CI, decision rules
A/B Test Design and Analysis: Signup Funnel You are designing and analyzing a two-arm A/B test for a signup funnel. Assume 1:1 traffic split and indep...
Explain mixed models and fixed vs random effects
In an applied DS setting, you are modeling an outcome (e.g., watch time per session, conversion, or rating) across multiple entities (e.g., users, cre...
Analyze Knights-and-Knaves Dialogue Variants
Knights and Knaves: Two Statements from B Context On an island, every person is either a knight (always tells the truth) or a knave (always lies). You...
Interpret p-values and common pitfalls
In a Fraud Data Science interview, you are asked “some p-value questions.” Answer the following in a fraud/experimentation context: 1) Define a p-valu...
Infer posterior after losing pick
Conditional probability after observing a loss You have three cats in a jumping contest: - Cat 1 (most athletic) wins with probability p1 - Cat 2 (mid...
Optimize interval-scoring strategy
Five-Round Interval-Estimation Game: Optimal Intervals and Risk Allocation You play five independent rounds. In round i, an unknown numeric answer A i...
Determine Claim Rate for Breakeven in Insurance Portfolio
Weather-Insurance Portfolio Profitability Setup You price a 12-month weather insurance policy. Customers pay premiums upfront for the year. Each polic...
Compute expected arc length on a circle
On the unit circle (radius \(1\), centered at the origin), pick three points independently and uniformly at random on the circumference. These three p...
Explain derivatives, YTM, and core statistics
You are interviewing for a quantitative/data role and are asked a mix of markets + statistics fundamentals. Part A — Markets & instruments 1. Derivati...
Set membership fee under investment constraints
Streaming membership pricing vs. content investment Context You are designing a monthly membership for a streaming service. Producing original shows i...
Diagnose and validate a ratio trend change
You are shown a weekly dispute_rate time series (disputes/succeeded_payments) that rises sharply, then partially reverts. Diagnose whether the change ...
Compute unit economics and insurance break-even
Subscription unit economics and insurance math. Assume no discounting and ignore taxes unless stated. Part A (15-month term): A subscription service c...
Compute break-even and simulate diaper inventory
You operate a cloth-diaper service with these weekly parameters: 350 babies served; charge $20 per baby; deliver 80 clean diapers per baby; average us...
Compare Bayesian and frequentist decisions
A/B Test With Beta–Binomial Posteriors and Decision-Making Under Asymmetric Costs You ran a two-arm A/B test on a binary KPI with independent Beta(1, ...
Infer distribution and choose robust statistics
A dataset of n=10,000 session revenues (USD) has: 65% zeros; mean=8.5; median=0; p90=30; p95=120; p99=620. (a) Propose a plausible generative model (e...
Evaluate ROI and payback for renewables
You’re advising NorthGrid Energy on a utility-scale renewables investment with the following Year-1 economics unless noted: upfront capex = $50,000,00...
Derive logistic regression and thresholds
Logistic Regression Deep Dive (Binary Classification) Assume a binary classification setting with observations {(x_i, y_i)} for i=1..n, where x_i ∈ R^...
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...
Contrast FCF vs NI; choose one statement
An asset-heavy company reports rising net income while free cash flow (FCF) is negative for three straight quarters. a) Explain when and why FCF can b...
Compute A/B significance, CI, and power
You run an A/B test for 7 days. Control A: 520 conversions out of 10,000 sessions. Variant B: 630 conversions out of 11,500 sessions. Use a calculator...