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."
Find minimal a for PSD of 3x3 matrix
PSD threshold for a 3×3 matrix with constant off-diagonal entries You are given the symmetric matrix with ones on the diagonal and a constant real val...
Determine intersection dimension of two 4D subspaces
This question evaluates linear algebra skills—specifically understanding of subspace dimensions, intersections and sums, and the dimension formula for...
Analyze skewed comments and sampling effects
Right‑Skewed Daily Comments: Location Stats and Sampling Distributions You’re analyzing daily user comments per user, which are right‑skewed count dat...
Test payment-accuracy lift with p-value and power
AB Test of Payment Accuracy (Two Proportions) Assume transactions in the two periods are independent and large enough for normal approximations. Defin...
Derive paying users over time with churn
This question evaluates the ability to model user conversion and churn with discrete-time recurrence relations, derive closed-form expressions for pay...
Analyze Cancellation Change with Statistics
A/B change in cancellation rate (before vs after) Context: You are evaluating a small product tweak intended to reduce cancellations. Treat each trip ...
Compute profit and break-even for memberships
This question evaluates a candidate's competency in unit economics, algebraic modeling, and sensitivity analysis for loyalty‑program pricing and profi...
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...
Derive expected meetings given nonempty room
Zero-Truncated Binomial: Random Room Assignment Setup - There are N rooms labeled 1, 2, ..., N. - K meetings are scheduled; each meeting independently...
Model user-level ad impression allocation
Random Assignment of Ad Impressions to Users Context - There are X distinct users and Y ad impressions (X ≥ 1, Y ≥ 0 integers). - Each impression is i...
Find premium share for break-even
This question evaluates a candidate's ability to construct and manipulate a linear financial model and perform break-even analysis using algebra, basi...
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...
Apply instrumental variables under interference
IV estimation for a ride‑sharing feature when A/B testing is infeasible due to interference Context You need to estimate the causal effect of a new ri...
Calculate Year-1 profit margin
This question evaluates a candidate's ability to perform applied financial math, including profit margin calculation, classification of costs into fix...
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...
Compare average unit profit under mix shift
This question evaluates competency in basic statistics and arithmetic applied to unit economics, specifically understanding weighted averages and sale...
Perform and justify t-tests
A/B Test: Compare Mean Watch Time Between Variants A and B Context: You ran an A/B test measuring per-user daily watch_time (in seconds). You obtained...
Calculate first-year profit margin
Profit Margin Calculation (Year 1) Context: A single product is sold in Year 1. m denotes million. Given: - Fixed costs: $375m - Units sold (Regular):...
Match prior-year profit with new fixed costs
This question evaluates cost–volume–profit analysis, unit economics, and algebraic modeling of fixed versus variable costs in a multi-product sales mi...
Decide launch with p=0.10 at alpha 0.05
This question evaluates a data scientist's competency in statistical inference and experiment decision-making, including frequentist hypothesis testin...