Maths problem

[1fast1]

If a fairly elementary solution is sought (as in this case), at some level, some "guess and check" (testing of potential solutions) is definitely required. The key is to systematise it and reduce the number of possibilities to be excluded (as I did in post 6).

 

As I said, if a completely rigorous solution is sought, the theory is very deep and frankly, the working will be even more involved, and not worth the trouble. Not unless the RHS is a ridiculously big number like 123456789, which makes "guess and check" without a computer almost impossible. And if allowed access to a PC, it's still faster to write a simple program to slog through a reduced number of possibilities than try to attack the problem head on with the theory of quadratic Diophantines.

Edited July 26, 2013 by Turboflat4

[Voodooman]

Please don't idolise me lah bro. I'm just a humble yisheng, and an especially humble one at that - definitely no surgeon earning the big bucks.

 

Continue to idolise T2, after all, I do too!

 

I've always been keen on Math/Physics - had a PSC OMS scholarship to do EE at Caltech, but turned it down to do Medicine here so that I obey father's wishes and be close to home. Bit late to regret now.

 

Wow, noble profession and filial son.

 

Yes, T2 has quite a following in MCF, got 2 camps. For the record, I am in the good camp. Haha....

[1fast1]

Wow, noble profession and filial son.

 

Thanks bro.

[Starhub]

How will such math qns applied to today society?

 

no need to bother to much :)

[1fast1]

How will such math qns applied to today society?

 

no need to bother to much :)

 

Maths is what I would consider to be the purest science; in fact it might transcend science, since it provides a formal logico-axiomatic "language" to all other sciences - starting with the most fundamental hard science, Physics, then working its way down to the Biological Sciences, and finally the "soft sciences" like Psychology and the Social Sciences.

 

A lot of people seem to be labouring under the misconception that mathematics, beyond basic arithmetic, has no application in their daily lives. They couldn't be more wrong.

 

For instance, every electrical appliance you use depends upon A.C. circuit theory for its design. That uses complex numbers, something most people think has no "real world" application. Every electronic device depends on quantum theory for its function - and that's formulated in very deep mathematical language involving complex numbers, partial differential equations, etc.

 

Every road you drive on, every bridge you cross depends upon mechanical/civil engineering, which uses concepts such as the stress tensor (something even more complicated than the vectors you might have learnt about at A levels) and hyperbolic trigonometry (to describe the catenary, which features in the design of bridges and arches).

 

This is MyCarForum. You should already be aware, if only on a purely abstract level, of how much engineering, and therefore math, goes into the design of your car. Supercars and F1 cars are designed to minimise drag, and to do that, they need to model fluid dynamics using the very complicated Navier-Stokes equations.

 

Medicine uses lots of math - and not just the basic calculations of concentrations and dosages used in drug administration. The study of how the body disposes of drugs (pharmacokinetics) uses lots of calculus, as does the study of enzyme kinetics (differential equations). Disciplines like epidemiology use advanced mathematical models - and these help bodies like the NEA plan how best to control dengue, for instance. Biomedical statistics applies fairly abstruse mathematical theory (essentially, the theory of probability) - every medicine you've taken has gone through rigorous clinical trials which use these statistical techniques to ensure that rigour. So even "life-saving" disciplines may use lots of advanced math.

 

Finance uses lots of complicated math. Just because you don't use it yourself in trading doesn't mean it doesn't go on behind the scenes. The basic model for options/derivatives pricing is the Black-Scholes, which employs fairly complicated partial differential equations.

 

Math pops its head up when we contemplate nature, often unexpectedly. Go read about the connection between the Golden Ratio, the logarithmic spiral the Fibonacci series and various natural phenomena like the nautilus shell.

 

At the highest level, when we contemplate the nature of reality itself, the mathematics can get very complicated. The General Theory of Relativity uses tensor fields and non-Euclidean geometry. Quantum mechanics uses group theory, a very abstract area of mathematics. Superstring theory talks about a Universe of ten dimensions!

 

So just because you're not aware of the applications of higher math (and frankly, what we've been discussing in this thread doesn't even qualify as higher math) to your everyday existence, please don't dismiss it.

[Sosaria]

How will such math qns applied to today society?

 

no need to bother to much :)

 

Even for practical engineers (not even those rocket science ones), the math can be required for basic estimation, or statistical analysis of data, from simple hypothesis test to regression test. Design also requires math to calculate stuff, else after machining, you find some parts too long, short, large, narrow, not enough material, etc.

 

Sometimes you find many unknown variables you need to optimise, and that's your math problem... Of course, the methods we use in real-life work need not be as theoretical as discussed here. We just use computer programs, math software, or even simple ol' excel spreadsheet to get the solutions by sheer calculation power. This is the "guess and check".

 

But it's not beautiful. Not elegant

 

And last of all you still need your math to tutor the young

Edited July 27, 2013 by Sosaria

[Sosaria]

...

So just because you're not aware of the applications of higher math (and frankly, what we've been discussing in this thread doesn't even qualify as higher math) to your everyday existence, please don't dismiss it.

 

*Hint* Primary school math ain't what it used to be in my day...!

[Rayleigh]

I kown who to consult if I need help.

[RadX]

instead of being a mathematician, you are technically a mad-a-mortician...considering the specimens u deal with.... [laugh]

[1fast1]

instead of being a mathematician, you are technically a mad-a-mortician...considering the specimens u deal with.... [laugh]

 

That description (based on popular myth about what you do) matches you better lah bro.

[RadX]

That description (based on popular myth about what you do) matches you better lah bro.

 

 

[laugh] back to the point, yes, maths would be the father of all science. Just like Physics, bio and chem. Most of biological interactions, require physics, eg, pressure, air differential, kinetics, etc...and most of them require maths, which would be the grandfadder of it all

[Hydrocarbon]

Maths is what I would consider to be the purest science; in fact it might transcend science, since it provides a formal logico-axiomatic "language" to all other sciences - starting with the most fundamental hard science, Physics, then working its way down to the Biological Sciences, and finally the "soft sciences" like Psychology and the Social Sciences.

 

So just because you're not aware of the applications of higher math (and frankly, what we've been discussing in this thread doesn't even qualify as higher math) to your everyday existence, please don't dismiss it.

 

Math is the language of science.

 

Propz to you, Turboflat4. Don't know what you are doing in your daily life, but your grasp of math is.. Thanks for sharing, I enjoyed reading your posts in this thread, and learning from you.

[1fast1]

Math is the language of science.

 

Propz to you, Turboflat4. Don't know what you are doing in your daily life, but your grasp of math is.. Thanks for sharing, I enjoyed reading your posts in this thread, and learning from you.

 

Thanks bro. Coming from you that means a lot.

Edited July 28, 2013 by Turboflat4

[Enye]

how to do by model method?

 

Allan had 60 stamps more than Becky. They each gave away some stamps. Becky gave away 2/5 of the number Allan had at first. Allan gave away 2/3 of the number Becky had at first. Both had an equal number of stamps left. How many stamps Allan have at first?

 

thanks guys.

[Enye]

another one

 

A,B,C and D each have some money.

 

A has 1/3 of the total B, C and D have.

 

B has 1/4 of the total A, C and D have

 

C has 1/5 of the total A, B and D have

 

D has $92.

 

How much do they have in total?

 

[Premacist]

This is PSLE question, I ask my son who is taking his PSLE this year to do, he told me Alan have 375 stamps at first. Is that the correct answer?

 

how to do by model method?

 

Allan had 60 stamps more than Becky. They each gave away some stamps. Becky gave away 2/5 of the number Allan had at first. Allan gave away 2/3 of the number Becky had at first. Both had an equal number of stamps left. How many stamps Allan have at first?

 

thanks guys.

 

[Little_prince]

another one

 

A,B,C and D each have some money.

 

A has 1/3 of the total B, C and D have.

 

B has 1/4 of the total A, C and D have

 

C has 1/5 of the total A, B and D have

 

D has $92.

 

How much do they have in total?

 

 

wah lau.

 

A= ( B+c+92)/3

 

b = (A+C+92)/4

 

C = ( A+ B+92)/5

 

solve lor.

 

sec sch math nia leh

[Enye]

This is PSLE question, I ask my son who is taking his PSLE this year to do, he told me Alan have 375 stamps at first. Is that the correct answer?

 

 

 

yes i do by simultaneous equations

 

dunno how to explain using model method

 

wah lau.

 

A= ( B+c+92)/3

 

b = (A+C+92)/4

 

C = ( A+ B+92)/5

 

solve lor.

 

sec sch math nia leh

 

pri school standard leh

 

cannot solve like that