4x+y+2z=100, x>y, y>z, x+y+z=j, 3x+z=k, j>k, j+k=100. WolframAlpha can only give me alternative forms or a solution involving 'real and imaginary parts of z'. Is there a solution I can count on my fingers? [more inside]
I've been asked at work to come up with a list of topics that could be included in a training course around basic maths for business people, and I am finding it hard to find suggestions for topics. [more inside]
Dear math people: please help me understand fractions and ratios intuitively. [more inside]
I've recently decided to transition to a new career path, accounting. Most firms round here do an online numeracy test as part of the application process. There is a type of % change question that often comes up and I can't find a proper answer about how to calculate it. There are two formulae suggested by different websites, but they give different answers. Which is right? (details inside) [more inside]
Dear Mefites, a long time ago I got a degree in graphic design but never worked in the industry. Along the way I somehow (don't remember how or why or when) became interested in math and I finished a graduate diploma in maths as a distance learning course in my free time. I am considering applying for masters programmes in maths or related subjects but ... can I? Should I? [more inside]
Mathematics-filter: If there are seven funds with various charges, how can I work out the allocation to these funds of a fixed amount so that the weighted mean charge is below a certain level and the allocations are of similar sizes? [more inside]
Say that I have a bag which contains 100 balls and every ball in the bag should be red, but it's possible that one or more of these balls is the wrong colour. How many balls should I look at to be 90% sure that all the balls are red? Or 95%? Or 99.9%? Talk me through how to work this out, please?
I know the price of something now and what the price was 2 years ago - how do I calculate that as an annual percentage increase? [more inside]
I'm looking to learn how to calculate probabilities for a multi-round dice game. I've researched this question some, and it looks like I might need to know how to use the multinomial distribution, but I can't find any good introductions. Please point me to the most layman-accessible educational material on this subject, and help me to help myself. [more inside]
Maths (math) people of the US: I need your help in working out if certain British conventions would be understood or standard in the US classroom. [more inside]
What is the difference between floating point accuracy and precision?
My son, who is finishing up third grade, loves math and especially the basic Algebra he's been doing. He is actually sad to be leaving school for the summer because he's so into it. How can I keep this going for him over the summer? Fun books, board games, computer (on-line and OSX) games? [more inside]
Did Anyone Invent Some New Math Stuff So They Could Solve A Problem Which Then Lead To a Technological Breakthrough?
Can you cite any examples where a technological breakthrough wasn't possible until there was some sort of mathematical breakthrough? [more inside]
But Sir, what is x? Teaching students algebra for the first time. They keep wanting to put values in for x, and write that down. E.g. x + x = . Becomes 1 + 1 = 2, in their books. Whereas I want x + x = 2x. Does anyone have any strategies, or techniques to overcome this? [more inside]
How do I reduce something by -800% when I'm working with a scale between -99% and 99%? [more inside]
I'm trying to find a website that teaches vector mathematics in lesson form. [more inside]
What is the next step of this Kenken? [more inside]
Please explain what calculus is to a dummy. [more inside]
Help with a Martin Gardner maths riddle, please! [more inside]
How do you animate a parameter in the OSX Grapher utility? [more inside]
I've annoyed myself by getting stuck attempting to work out a silly maths problem relating to permutations. It's an extension of the 'how many odd socks do I have to pull out of a drawer before I find a pair' problem. Only my theoretical sock-wearer has three legs. And a penchant for odd socks. [more inside]
When did "Maths" change to "Math" in American English? Or is it the other way around? [more inside]
Best books, websites, lecture series on game theory and its applications for smart people who understand mathematics but can't stand trawling through pages of unnecessary complex formulae?
GISfilter -- I have a PostGIS table containing spatial data in the form of a few thousand shapefiles. Anybody know a quick way I can move *all* of them by about 40 metres? [more inside]
Applied Math Filter: Help me use math! I'd like to learn more about mathematics and it's practical applications - particularly in Computer Science [more inside]
How can I help my 6 1/2 year old son to *get* maths? It hasn't clicked with him at all and I find myself getting frustrated with having to repeat really basic stuff when helping him with his homework. I'm not a maths genius myself and I really don't want to put him off by getting cranky because he's just not getting it. How do I help him get it? [more inside]
Teaching a university course for the first time: any tips or suggestions? [more inside]
Where am I going wrong with this (very simple) implicit derivative? [more inside]
Why is it that when I solve the inequality 0 ≤ arccos(x) <> cos(π/4)? Why do the operators switch direction?> [more inside]
is there a book on the mathematics of chess? [more inside]
ABC x D = BADC. What single numbers (1-9) do the letters represent? Is there any way to arrive at the answer (a) by logical deduction all the way rather than with some trial-and-error and (b) so that a 10-year-old can follow the logic? [more inside]
(x + y)-(x*y)=79. What are x and y? [more inside]
My maths skills are rubbish. Help me understand modulus remainders [more inside]
Is there a mathematical technique for simplifying ratios/fractions? [more inside]
A crystal consists of 100,000,000 layers of atoms such that there is 1 atom in the first layer, 3 in the second, 6 in the third, 10 in the fourth, 15 in the fifth, and so forth. Exactly how many atoms are there in the entire crystal? [more inside]
I am trying to find some good interactive Maths tutorial software which goes from basic algebra through to Differential Equations and maybe beyond. Can anyone recommend anything with the emphasis on the interactive side - something which can keep me interested so nothing too dry - a nice colorful multimedia approach would be ideal.
How can a major key sound confident and happy, while a minor key can sound sinister or sad? Is it just centuries of musical brainwashing, or is there a real mathematical explanation?
I'd like to learn Math. I'm particularly interested in learning trig and calculus. I'm don't need to learn these disciplines for any purpose. I'm just interested. I'm a reasonably bright guy, with a logical mind (I've worked as a programmer), and I'm a good self-learner. I'm not in a rush (don't mind working at this for a few years). What books/resources would you recommend? I should probably go all the way back to Algebra, which is pretty much where I left off in High School years ago.