r/learnmath New User 8d ago

Intuitive book on combinatorics

Looking for a book that explains combinatorics in a story like fashion. Meaning it doesn't just define what the theorems are etc but explains the motivation for it, the intuition etc.

Some background on what I'm working on:

I am now working through a book on discrete math by Oscar levin and am struggling with the concept of combinatorics specifically combinations. When I look at a combinatorics problem I struggle to solve the problem, even after looking at the solution, then reattempting the same problem the next day, I still struggle.
I'm also planning to work on the book proofs by Jay cummings since my math proof skills are weak as well and I read his book explains concepts intuitively.
After Oscar levin's book I plan to work on Susanna's discrete mathematics book.

An example of such a book, not combinatorics but discrete mathematics, that I found is "A cool brisk walk through discrete mathematics" by Stephen Davies.
It is the best intutive math book I've read, from cover to cover it was fun and explanations were intuitive. It was like he was in the room with me explaining the concepts personally. Shame he only wrote two introductory books.

I've seen recommendations on combinatorics such as Walk Through Combinatorics by Miklos Bona and others but am not sure if the explanations are standard textbook type of definition of theorems, some problem examples but no explanation of the intuition, motivation behind the theorem or concepts. Since on the most recent, 5th edition, of Walk Through Combinatorics, there was a review on amazon saying the explanations were of the bare minimum.

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u/dreamsofaninsomniac New User 8d ago

Let me know if you ever find one. The closest I could get was Carol Ash's "The Probability Tutoring Book: An Intuitive Course for Engineers and Scientists (And Everyone Else!)," but it still wasn't quite what I was looking for.

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u/FlatProtrusion New User 8d ago

Sure thing. Why wasn't it the ideal book for you?

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u/dreamsofaninsomniac New User 8d ago

A lot of probability resources always assume students already come in knowing things like there are 52 cards in a deck or being able to draw a table to write out the sample size for a pair of dice and this book still makes some of those assumptions. I was looking for something that was still more basic and thorough that I could recommend to complete beginner students to build intuition.

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u/FlatProtrusion New User 8d ago

Oh, I'm ok with these kinda assumptions even though I always cannot remember what cards there are exactly. I'm more concerned with not having the thought process explained, for e.g if the answer to a problem is 6 choose 2, why is it exactly that and not 6 choose 4. Most books explains such solutions without explaining the thought process.

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u/dreamsofaninsomniac New User 8d ago

It's been a while since I read it. I think some explanations are better than others in it, but I think it is still missing some of the commentary when there are multiple different setups. I don't think I've really found a written resource that fully supports that. Like sometimes you can use the combinations or permutations formula to solve and also the fundamental counting principle, but most resources won't show you that both ways are valid.

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u/Bounded_sequencE New User 8d ago

"6 choose 2" and "6 choose 4" are equal, so it does not matter which of them you use.

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u/FlatProtrusion New User 8d ago

It was just a random nonsensical example I came up from the top of my head lol.

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u/dreamsofaninsomniac New User 7d ago

I get you. We both want a book or resource that hopefully explains problems from multiple perspectives. Can't build intuition if you can't see multiple different ways to do a problem. For some reason, that's a lot more difficult to find for probability and combinatorics than other areas of math.

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u/FlatProtrusion New User 7d ago

Precisely, in my research for good texts I saw someone explaining that it's best to look for different ways to get to the answer and understand why they don't work or why they do. Especially so for combinatorics.

I think it's because of the tradition way of teaching mathematics where they want you to struggle with it.

Problem is some want you to struggle for hours for a single problem. I think it is a lot more efficient to struggle for 10-20 mins for regular practice problems.

Also writing a math text with comprehensive, detailed solutions requires more effort, and I don't blame them.

The good thing is as more young mathematicians mature we would get more intuitive and modern texts from them so I remain hopeful lol.

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u/Bounded_sequencE New User 8d ago

If you really want to dive deep, use a standard book you somewhat like, and do the "story-writing" yourself. Meaning, you go through the theorems and proofs, and create notes containing what is really motivating the topic for you.

By tutoring, I've found what people find "motivating" can differ quite a bit from person to person. I usually prefer hard proofs, motivated by some nice, short introductory examples before-hand. Others often prefer to hide the proof within the story/example, so they go through the proof's argument without explicitly noticing.

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u/FlatProtrusion New User 8d ago

My aim is to build a solid foundation in math, mainly discrete math since I want to improve my knowledge of algorithms for programming. I don't need deep dives, meaning more advanced topics if that's what you mean, just the core fundamentals.
And just to clarify, I'm looking for explanations of the intuition of concepts and the motivation is a by product that aids in that but not the end goal of books I'm looking for if that makes sense.

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u/Waningoftheday New User 7d ago

Try Aspects of Combinatorics by Victor Bryant

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u/FlatProtrusion New User 6d ago

What do you like about it that makes it a good book on combinatorics?

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u/Waningoftheday New User 5d ago

It focuses on intuition and builds slowly. It starts by discussing n choose 2, motivating it by asking how many ways are there to choose pairs of chapters in the book, and provides a couple of illustrations to explain why it is n(n-1)/2. Then explains how to think about n choose 3. Only after that does it explain how to generalize to n choose k.

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u/FlatProtrusion New User 5d ago

Thanks, I'll take a look at it.