Data Scientist Statistics & Math Interview Questions
Practice 463 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."
Correct length-biased sampling from family-size survey
In a town, you visit a school and ask 100 kids: “How many children are in your family?” You observe: - 50 kids say their family has 1 child - 20 kids ...
Explain Linear Regression Assumptions
Suppose you are using ordinary least squares linear regression to model a continuous business outcome such as weekly user spend from several features,...
Derive mean and variance of x̄
Let \(X_1, X_2, \dots, X_n\) be random variables, and define the sample mean as \(\bar X = \frac{1}{n}\sum_{i=1}^n X_i\). 1. Assume the variables are ...
Diagnose and fix a flight-delay modeling setup
Flight Delay Modeling: Binary Target, Features, and Diagnostics You are modeling the probability that a flight arrives with a delay greater than 15 mi...
Explain Bootstrap and Statistical Inference
Answer the following statistics questions at interview depth: - What is the bootstrap? Describe the resampling procedure, when it is useful, and what ...
Calculate Precision, Recall, and F1
You are given a list of binary classification outputs such as [{"actual": 1, "predicted": 0, "confidence": 0.93}, ...], where class 1 is the positive ...
Compute probability an account is fake
A platform uses an automated classifier to flag potentially fake accounts. Assume: - Base rate: 2% of accounts are fake. - The classifier flags a fake...
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...
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...
Estimate laptops in an office
Give a back-of-the-envelope estimate for how many laptops are physically present in a typical corporate office at a given moment. State your assumptio...
Solve Markov, OLS-rotation, and coin-toss probability
Answer the following three interview questions. 1) Basic properties of a Markov (transition) matrix Let \(P\) be a transition matrix of a (time-homoge...
Use confusion matrix to choose model metric
Scenario You built a binary classifier (e.g., fraud detection, churn risk, medical screening, spam). You are given a confusion matrix on a validation ...
How do you compute expected return for two projects?
Case: Choose between two TV projects under uncertainty You are evaluating two projects: - Project A: "Analyst" (an existing TV show you can continue i...
Analyze the Accident-Rate Spike
A monthly line chart shows the accident rate for Uber trips in one city. The accident rate increases sharply from June through November, then drops qu...
Compute robust inference under skew and outliers
A/B test with skew, outliers, heteroskedasticity, missingness, and multiplicity You are comparing two independent product variants that produce a cont...
Estimate constant under absolute loss
Suppose you have observed target values \(y_1, y_2, \dots, y_n\), and you want to fit the simplest possible model that predicts the same constant valu...
How would you critique this regression?
You are reviewing a modeling workflow from another data scientist. Business context A website receives traffic from Google Search. Define the response...
Solve Market-Risk and Probability Questions
Answer the following quantitative interview questions for a market-risk role: 1. Stress testing WTI and Brent Design a stress-testing framework for...
Solve probability and expectation problems
You are asked to solve the following probability and mathematical interview problems: 1. Squid Game glass bridge: There are B sequential bridge steps....
Estimate total attendance from size-biased reservation sample
You run a restaurant with N = 10,000 reservations in a day. Each reservation j has: - Reserved party size: \(R_j\) (positive integer) - Actual number ...