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."
Why Use a t-Statistic?
In the context of an A/B test or a linear regression, explain why the t-statistic is a useful measure for evaluating whether an estimated effect diffe...
Choose Classification Metrics Under Asymmetric Costs
You are evaluating a binary classification model for a business problem. Explain how to use a confusion matrix to compute and interpret: - precision, ...
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 ...
Compute Optimal Die Re-roll Strategy
A fair six-sided die pays its face value in dollars. You may roll up to three times total. - After the first or second roll, you may either keep the o...
Can bootstrap help reduce variance
An interviewer asks: “Can bootstrap help reduce variance?” Answer this question precisely. Distinguish between: 1) Using the bootstrap to estimate var...
Compute posterior for biased coin after 3H1T
You are given a coin known to be biased: one face lands with probability 2/3 and the other with probability 1/3, but you do not know whether Heads is ...
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...
Should Uber double member discounts?
Uber is considering increasing the member discount on rides from 5 percent to 10 percent. This can affect rider demand, driver supply, marketplace bal...
Solve Classic Probability Questions
An onsite interview included the following independent probability and expectation questions: 1. Squid Game bridge problem. In the classic glass-bridg...
How do you compute expected return for two projects?
Case: A TV studio's project & divestiture decisions under uncertainty You are the CEO of a media/streaming company. You run an existing TV show, "Anal...
Find constant minimizing absolute error
You have a dataset of real-valued targets \(y_1, y_2, \dots, y_n\). You want to fit a constant predictor (no features): - Prediction: \(\hat y_i = c\)...
Solve Market-Risk and Probability Questions
Question Answer the following quantitative interview questions for a market-risk / data-scientist screen at Morgan Stanley. 1. Stress testing WTI and ...
Implement robust one/two-sided p-value function
Implement p_value(stat, alternative, dist, df=None) Context: You're building a small, production-quality helper to compute p-values for common one- an...
Find probability of overlapping blooms
Overlap Probability of Two Random Bloom Periods Assumptions - Time is measured in days over a 30-day horizon. - Each flower begins blooming once, at a...
Compute probabilities and expectations in random processes
This is a rapid-fire probability and expectation round: a sequence of short, self-contained brain-teasers solved on a whiteboard. The interviewer expe...
Calculate a Confidence Interval
Suppose an online experiment compares treatment and control on conversion rate. Treatment has x1 conversions out of n1 users, and control has x0 conve...
Explain why the t-statistic helps
Suppose you estimate an effect size \(\hat{\beta}\) in a regression model or an A/B test and compute a standard error \(SE(\hat{\beta})\). Explain why...
Find next terms in sequences
Pattern Recognition: Find the Rule and Next Term You are given 8 number sequences. For each sequence: - Identify a clear rule that generates the terms...
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,...
Determine Probability of Single Ride on Following Day
Determine Probability of a Single Ride on the Following Day A pricing experiment gives each new rider two ride opportunities on day 1. For each offere...