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."
Explain Central Limit Theorem and Its Limitations
Statistics Concepts and Disease-Test Evaluation Context You are assessing core statistical concepts used in evaluating diagnostic tests and in data sc...
Explain Type I vs. Type II Errors in A/B Testing
A/B Testing Errors and Estimation Under Skewed Metrics Context You are analyzing an A/B experiment for a product feature. You need to explain the stat...
Understand Propensity Score Matching in Business Analytics
Propensity Score Matching (PSM) in Observational Product Data Context You work on a growth analytics team estimating causal effects (e.g., of a featur...
Identify Metrics to Detect Fake-Account Activity on Facebook
Detecting and Measuring Fake Accounts Scenario Facebook wants to understand and curb fake-account activity both over the past month and at sign-up tim...
Determine Probability of Friend Request Being Fake
Scenario You operate a platform where 95% of accounts are real and 5% are fake. Fake accounts send 10 times as many friend requests per account as rea...
Identify Probability of Request Originating from Bad User
Measuring Abuse in Friend-Requests: Bayes, Identification, and Precision Scenario A social-network platform wants to measure and control abuse. Five p...
Compute multi-step Markov probabilities and estimate transitions
Problem (Markov Chain Probabilities) You are working with a discrete-time Markov chain over a finite set of states $S = \{s_1, \dots, s_n\}$. The chai...
Derive eigenvalues and sum for inverse matrix
Eigenvalues of an Inverse and Their Sum Context Let A be an invertible n×n matrix (over the real or complex numbers). All eigenvalues of A are nonzero...
Compute expected coin flips to meet on octagon
Meeting Time on a Random Walk Around an Octagon Problem Two independent particles start at opposite vertices (four edges apart) of a regular octagon. ...
Explain Bias-Variance Trade-off Simply for Stakeholders
Scenario You are in a technical phone screen for a Data Scientist role. The interviewer asks you to communicate a core modeling concept in plain langu...
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 Posterior Probability of Flagged User Being Bad Actor
Bayesian inference for abuse detection with error control Setup A platform runs a binary classifier that flags users who might be bad actors. Let: - p...
Determine Posterior Probability of Bad User Prediction
Evaluating a Classifier That Flags Bad Actors Question You are evaluating a binary classifier for detecting bad actors among users. Given: - Prevalenc...
Design A/B Test to Evaluate Algorithm's Revenue Impact
A/B Test Design for a New Recommendation Algorithm Context You are evaluating a new recommendation algorithm in a consumer marketplace app (e.g., brow...
Calculate Expected Impressions and Probability for Users
Random Allocation of Y Ad Impressions to X Users Setup (assumptions) - There are X distinct users and Y ad impressions. - Each impression is assigned ...
Compute and estimate Markov transition probabilities
A system is modeled as a discrete-time Markov chain over m states S = {s1, s2, ..., sm}. Part A (multi-step probabilities): - You are given a row-stoc...
Explain a stochastic process simply
Question In plain, non-technical language, explain what a stochastic process is to a hiring manager. Include: - An intuitive definition (what varies, ...
Analyze Newton-Raphson Convergence, Choose Sigma, and Derive Vega
Context You are given the market price of a European option and must infer the Black–Scholes implied volatility. This requires solving for the volatil...
Solve coin probability and Bayesian inference problems
Coin-Flip Statistics: Pattern Racing, Runs, and Bayesian Updating You are given three independent questions about fair coin tossing and Bayesian updat...
How to compute correlation from variances
You have two random variables \(X\) and \(Y\). You are told: - \(\mathrm{Var}(X+Y)\) - \(\mathrm{Var}(X)\) 1) Is this information sufficient to determ...