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."
Choose better bank queue and describe distributions
You are interviewing for a data role and are asked several probability/distribution questions. 1) Bank queue choice (queueing intuition) A bank has 5 ...
How do you detect and fix multicollinearity?
In a regression-style model (e.g., linear regression or logistic regression) you suspect multicollinearity among features. 1) What is multicollinearit...
Compute an A/B test p-value by hand
In an A/B test on a game feature, you measure conversion rate (binary outcome). - Control: n₁ = 1000 users, x₁ = 120 conversions - Treatment: n₂ = 980...
Calculate Probability of Honest and Relevant Chatbot Answers
Chatbot Evaluation: Honesty and Relevance Scenario You are evaluating a customer-service chatbot. Define two events for any given answer: - H: the ans...
Explain Statistical Concepts in A/B Testing and Corrections
A/B Testing: p-values, Power, and Error Rates with Multiple Comparisons Context You are reviewing the results of an online A/B experiment. Stakeholder...
Construct a 95% Confidence Interval for Comment Counts
Comment Activity Analysis: Mean CI, Sampling Distribution, and 95th Percentile Context You have a simple random sample of users with their comment cou...
Determine Probability of Fourth Good Response After Three Successes
Evaluating Good-Response Rates for Chatbot Outputs Context You are evaluating chatbot/LLM responses. Treat each response as a Bernoulli trial (good vs...
Prove Equal Probability Impossible with Relabeled Dice Faces
Uniform Sums from Two Relabeled Fair Dice Setup You have two fair six-sided dice. You may relabel each die's faces with integers; duplicates are allow...
Evaluate Probability of Positive User Comments and Model Performance
Social-Media Positivity: Independence and Model Comparison Context You are evaluating user comment sentiment and the performance of two models that cl...
Calculate Conversion Probability for Male Ad Impressions
Scenario You are estimating conversion probabilities for ad impressions. Before knowing a user's gender, the overall conversion rate is 2%. Given - P(...
Calculate Expected Streaks in Coin Toss Sequence
Expected Number of Streaks in Coin Tosses Scenario You toss a coin repeatedly. A "streak" (a run) begins on the first toss and whenever the current to...
Estimate and Derive Regression Coefficient for X on y
Statistics & Probability Onsite — Two-Part Question Context - You have a simple linear data-generating process: y = X + ε, where X and ε are independe...
Describe Facebook User Comment Distribution Shape and Justification
Characterizing Comments per User on Facebook Context You are analyzing the number of comments made by each user over a fixed time window (e.g., 30 day...
Calculate Particle Survival Probability After Time t
Radioactive-Decay Style Probability Context You have 100 identical, independent particles. Each particle's lifetime is exponentially distributed with ...
Explain multicollinearity and OLS assumptions
Linear Regression Technical Screen: OLS Assumptions and Multicollinearity Context: You are asked to summarize core OLS assumptions, explain multicolli...
Test Whether Two Samples Come From the Same Distribution
Question You have two datasets, sample A and sample B. They might come from two versions of a system, two cities, or two periods of autonomous-driving...
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...
Test if one value comes from N(μ,σ²)
Assume the population is N(μ, σ²) with μ and σ known. You observe a single value x = 1.37. Formulate a two-sided hypothesis test H0: X ~ N(μ, σ²) vs H...
Plan and analyze an A/B test
A/B Test: Power, Clustering, Sequential Monitoring, Multiple Comparisons, and Diagnostics Context You are planning an A/B test for a dashboard change ...
Control error under multiple testing
Multiple Testing and Sequential Monitoring with 1 Primary and 12 Secondary Metrics Context You are monitoring an A/B experiment over 4 weekly looks. T...