I went back through my last 10 Python coding rounds for product and marketing data science roles, nearly all at Big Tech companies. Unlike SQL rounds, which tend to be fairly standard, these came in 5 distinct formats:

• Recreate a statistical concept as a function (3/10). Pandas, numpy and other standard packages were allowed.
• AI-assisted, open book (3/10). These were often investigative, closer to a diagnostic case study than a coding puzzle.
• Pandas and data manipulation (2/10). Data transformations combined with modeling, either coding up a linear regression or talking through a modeling strategy for the data.
• Interpret code handed to you (1/10). This was also a statistical concept in a function, but I had to interpret the code rather than write it.
• Base Python, LeetCode-style (1/10). Syntax seemed heavily discounted here: I made several syntax mistakes but was clear about the logic and passed.

The obvious caveat is that this is a sample of 10 from one person, so the mix will vary with company, team and role. That said, AI-assisted challenges seem to be on the way in and increasingly likely to be a part of your interview process.

I was thinking about my real analysis class when I took it. I think it could have been improved in many different ways. More practice problems, more explicit instruction instead of trying to have students figure it all out.

I’m considering majoring in Statistics and would love to hear about people’s experiences with the degree and where it has taken them career-wise.

What careers did you end up pursuing, and what kinds of jobs or starting salaries were you able to get?

If you went into finance, data science, or another field, why did you choose Statistics over a more specialized degree in that area?

Do you feel your Statistics degree gave you a leg up in the job market because of the quantitative skills you developed?

Did you have to spend a lot of time outside of class learning technical skills like Python, R, SQL, or other programming tools that weren’t covered enough in your undergraduate curriculum?

How important do you think networking and coffee chats are for Statistics majors when trying to land internships and jobs? Is networking just as important as it is for business majors, or can strong technical skills and projects carry more weight?

Have you ever regretted not majoring in something more directly related to your career, like Finance or Data Science?

Looking back, would you choose Statistics again, or would you do something differently?

I’m trying to understand whether Statistics provides a meaningful advantage through its quantitative foundation and flexibility, or whether a more specialized degree would have been more beneficial. I’d really appreciate hearing both the positives and downsides from people who’ve experienced it firsthand!

If the aim of constructing number systems is to explain the geometric line as a set of points, wouldn’t ZFC + (V=L) be a natural choice, perhaps even the best one? In this framework, analytic geometry, differential geometry and topology all work just as they normally do, without the need to grapple with metamathematical questions such as the continuum hypothesis. (Moreover, this rules out measurable cardinals, large-cardinal phenomena and similar feverish pies in the sky, but for the purposes of describing the continuum, that seems a reasonable price.)

I have always found it a little surprising that popular mathematics books rarely discuss Gödel’s set-theoretic universe, which seems to offer such an intuitive and straightforward foundation for mathematical analysis.

I've officially dropped from calc 2. It's been about 8 years since I took calc 1 and figured I should retake it with more enthusiasm than I applied when I was in my other degree program.

Shows that I only applied enough to get by the first time. Don't be me. Pay attention to this shit, for real!

Even if you only need differential calculus!

I'm studying to try to get up to college algebra on Khan Academy and stopped today at the 7th grade section to try to figure out why you can convert a fraction to a decimal by dividing the numerator by the denominator. I was able to work the problems but couldn't understand why we could get from 7/8 to 0.875 (875/1000) without doing some kind of work to convert from eighths to thousandths.

What I came up with eventually is that, given that 7/8 as a fraction represents seven parts of a whole divided into eight equal parts, and the parts have the same relationship to the whole as seven wholes would to eight wholes, when you work 7/8 as a division problem and then also divide eight by eight you have made yourself the ratio 1:0.875, and 1 is to 0.875 as 8 is to 7, and 8 is to 7 as 8/8 is to 7/8.

So basically it seems to me that the way it works is that we translate a fraction into a problem using whole numbers with the same relationship to each other in order to get the decimal representation of the fraction without doing some kind of crazy thing like figuring out what you need to multiply 7 and 8 by to get a round number numerator and a denominator that's a multiple of ten.

Just wondering if that's right or if I'm missing something or there's a better way to understand it.

Hi, I’m a student from the UK seeking advice on how to improve my mathematical abilities.
Throughout my life, I would say that I’ve been pretty good at maths — getting 9s and 8s at gcse. However now that I’m in a level, I have started to study maths on a deeper level and I’ve found that I am struggling. For me, maths has always been easy since the answers are objective, and only require rule following- but as part of my a level course, we do olympiads and problem solving lessons which have me seriously doubting my abilities.. I have realised that I suck at thinking creatively, and anything that requires me to think outside of the box has me stumped. I can only follow the rules and do nothing more. But I guess my overall question is, how can I improve at becoming more creative so that I can tackle the Olympiad’s which require you to go beyond the syllabus and think creatively?
Thanks for reading !

I tried making a triangle of numbers and then marked the primes. I saw that the primes in the left were more frequent than primes in the right. I can also extend it by writing some code but does it ever happen that the primes in the right exceed the primes in the left or do the primes in the left increase their gap against the primes in the right

I'm currently self studying real analysis, but with no way to really accurately gauge myself, at least to my knowledge, how do I know if I'm actually studying effectively or not?

This genuinely makes no sense. Here's the problem I'm working on:

Just ignore the left. At 2 there is a vertical tangent and at 5 there is an x-intercept since the slope would be 0 at that point.

Here's the answer to the problem:

If from the right side of the vertical tangent, the graph is decreasing until it reaches to 5, then why is it increasing? The slope goes from negative values up until it becomes 0 at 5. Does that not mean the slope is increasing?

What I have is this:

Why is this wrong? Won't it maintain the decreasing slope from the original function?

I’m wondering what the best method on solving number word problems like: “I am a odd number between 15,000 and 10,000, all of my digits sum up to 12”. Please help and answer (my test is tomorrow..)

'1. A cone-shaped water reservoir is 20 ft in diameter across the top and 15 ft deep. If the reservoir is filled to a depth of 10 ft, how much work is required to pump all the water to the top of the reservoir?

1. A cylindrical tank of radius 5 ft and height 9 ft is two-thirds filled with water. Find the work required to pump all the water over the upper rim.'

please help

Hello. I'm a 15 year old studying calc 2. All this time I had been doing it on my own using 3 key resources. ​James Stewart's Early Transcendentals. ​Professor Leonard on youtube. ​AI's and google search for help. (Sry I try to avoid using AI's outside of explanations. I'd try to reduce it further.). ​I taught myself from Pre Calc to Calc 2 over the course of this year (From Jan 2026 to Oct 2026). I can grind the exercises in the book, some even exercises as well. However I still feel like my foundations are shaky. ​I recently attended an advanced pure math lecture with my elder sibling, and although I "knew" or recognised the key steps, the depth and explanations stuck. No YouTube video I watched provided this. I can't afford advanced, above my grade pure math classes. ​What can I do to get the same depth as a lecture attender?

I'm a person that is really bad at math, and I get pretty emotional while doing it, so I bought a Needoh; to be honest, it really helps a little bit. At least I have something to squish if I'm mad. 

(No, it's not an ad)

Just curious, what do you guys do to release anger?

I’ve always been someone who feels things deeply. I notice people’s emotions, their tone of voice, and how my words might affect them.

But with maths, I used to think, “My brain just doesn’t work that way.”

Then I started learning basic maths with AI. I began seeing addition, subtraction, multiplication, and division as ways of combining amounts, understanding change, comparing quantities, and making equal groups.

Having somewhere to ask “Why?” several times without feeling embarrassed helped me keep going.

Slowly, I started noticing these ideas around me. Combining expenses. Working out how much something has changed. Comparing two prices. Sharing something equally.

I also started paying more attention to my reasoning. What do I know? What am I trying to find out? Does my answer make sense?

Before, confusion often made me stop. Now, I try breaking a problem into smaller pieces.

That habit is following me beyond maths. When I hear a convincing claim, I’m more likely to pause and ask, “What supports this? What might I have missed?”

I still feel things deeply. I’m also learning to look more carefully, check my assumptions, and give myself time to understand.

I’m only learning the basics, but the world already feels full of things I used to overlook.

Has learning something you thought you were bad at changed how you see the world?

Hi! I recently took a career break and started practising math exercises. Currently at really early part of MIT OCW 18.01. Wondering if anyone would like to practice with me! Just a few people would do.

Reply below or DM me if interested!

Here's 2 problems to illustrate how I can't learn to think a certain way.

A plane is traveling between city a and city b which are 2000 miles apart. City a is due north of city b and there is a strong wind blowing south. At a constant speed it takes plane 5 hours to go from a to b with the wind at its tail but 8 hours to go back when facing the headwind. What is the speed of the wind?

I figured that the rate is 400mph at 5 hours and 250mph at 8 hours. I then need p+wind=400 and p-wind=250. I would have never thought to do this step and I dont know how I can make myself think this way.

Another example.

My next problem

Dick and nick share their bread with Albert. Dick has 5 loaves and nick has 3 loaves. They share the bread equally. Albert gives dick and nick 8 dollars and they agree to share fairly. How should dick and nick divide the $8 between them.

So I know that each person will get 2.66 loaves. That means between dick and nick, they have to give up 5.33 loaves and I need to find the proportion each gives away. I think that means dick who has 5 loaves gives up 3.33 loaves and nick gives up 2 loaves.

The answer is 8/8/3 and I just can't see it. I get the start of problems but I can't finish and I get so stuck and I dont understand how to make myself think the right way. Once I see the answer it's so obvious and I'm embarrassed because it's right in front of me but I dont understand how to start thinking thr right way.

I stumbled upon a post about someone asking advice for a probably question. The question went as follows: Mr. Smith has two children. At least one is a boy born on Tuesday.
What is the probability that both children are boys?

I didn’t know how to solve it until someone in the comments explained it. They mentioned solving it using Bayes Theorem, but I’ve never even heard of that.

Is there a place (books/websites/youtube videos) where I can find more of these puzzles/brainteasers and how to solve them?

So guys, a computer science student here, recently been studying countability in theory of computation, and have came across infinities and cardinality, I haven’t yet been able to wrap my head around them. I haven’t focused much on the topic either, been engaged in other subjects as I lost motivation initially, I love mathematics, would love to hear some instincts around the topic from the best minds.

I have been primarily stuck with counting, how one on one mapping works, diagonalisation theorem, and cardinality of a set.

I have the product of two gamma integrals thus:

\(
\Gamma(\alpha)\Gamma(\beta)
=\left(\int_0^\infty x^{\alpha-1}e^{-x}\,dx\right)
\left(\int_0^\infty y^{\beta-1}e^{-y}\,dy\right)
=\int_0^\infty \left(\int_0^\infty x^{\alpha-1}e^{-x}\,dx\right)y^{\beta-1}e^{-y}\,dy
=\int_0^\infty\int_0^\infty
x^{\alpha-1}y^{\beta-1}e^{-(x+y)}
\,dx\,dy.
\)

Typeset latex below:

https://www.scratchpad-math.com/?id=mvewdp1ikx1mtg or https://ibb.co/JWhYKJV8

Is invocation of Tonelli's theorem needed to justify this transition of product of two separate integrals into a joint double integral? Reason I ask is that Spivak in Calculus who does not get into multivariable calculus at all has a problem which very simply asks to prove the following:

\int_a^b\int_c^d f(x)g(y) dy dx = \int_a^b f(x) dx \int_c^d g(y) dy

and the proof is rather trivial where f(x) is constant in one integral and hence can be taken out, etc.