48÷2(9+3) = ????

[sammyg2]

BTW, I gave this equasion to a young hot-shot engineer that works for me who recently earned his MBA from Pepperdine.
His answer? 2.

I told him it was 288. He disagreed and then he got out his fancy scientific graphic calcumalator thingy and said oh, I guess it is 288.

Stoopid math.

[wdfifteen]

Originally Posted by masraum

Right, but according to the other guy.....

1. Exponents
2. Stuff inside parentheses
3. Stuff right next to but outside parentheses
4. Multiplication from left to right except the stuff in rule 3 that's stuck to the outside of the parentheses
5. Addition

According to him (not me)...

48÷2(12)-->48÷24=2

Which is the correct answer.

[romad]

Its not a correctly written equations, that is the only conclusion. Time for all of us to move on.

[svandamme]

flipping hell, this is turning into the "Is there a god" thread.
There is nothing wrong with the equations, there's just misinterpretation by some.. it's 288 as is.

[wdfifteen]

Originally Posted by krystar

yes it does

1/3 = 0.3333...
3*1/3 = 0.9999...
1 = 0.999...

Are you serious? This thread has gotten so goofy I can't tell.

[Porsche-O-Phile]

I'm not reading 15 pages of this...

Answer is 288.

48 (divided by) 2 (9+3)

do the parentheses first:

48 (divided by) 2 (12)

is the same as:

48 (divided by) 2 (times) 12

resolve the same-tier operations (multiplication/division) left to right:

24 (times) 12 = 288

WTF guys? This is basic stuff. No wonder the U.S. is getting its ass kicked right now if we've got 15 pages debating this.

[krystar]

Originally Posted by wdfifteen

Are you serious? This thread has gotten so goofy I can't tell.

about 0.9repeating = 1? yea....that's serious hehe

[krystar]

Originally Posted by Porsche-O-Phile

WTF guys? This is basic stuff. No wonder the U.S. is getting its ass kicked right now if we've got 15 pages debating this.

i wonder. if we polled a EU or Asian based forum, would we still see the wide gap in discussion? this could really be the sign of flaws of primary education system in US.

[DARISC]

Originally Posted by romad

It's not a correctly written equation...

Do you consider inelegant proofs to be incorrect because they are inelegant?

[wdfifteen]

Originally Posted by krystar

about 0.9repeating = 1? yea....that's serious hehe

I was asking about 1/3 = .3333 .....

I studied engineering, not goofy math problems.
.333 .... is a repeating decimal approximation of 1/3. Every time you use it in a calculation you introduce a rounding error, which you MUST be aware of if you are designing something (like a bridge). You illustrated this in your post when you got the answer 1=.999 ....
It is better to use the rational relationship as much as possible because it is accurate and the decimal is an approximation.

[romad]

The WHOLE internet can not make a conclusion. Has nothing to do with the education system. They sell t-shirts with the equation on it as a question mark. Its a flawed equation. Its has been for years. Just like writing a bad sentence. 2 is no more correct than 288

[krystar]

well in engineering scope, there is no such thing as infinitely repeating. but in mathematics, there is. in engineering and physics and alot of other applied math fields, precision actually matters. in pure math, 1=1.0=1.00=1.00000000 but in engineering, we know those are completely different.

[wdfifteen]

Originally Posted by krystar

well in engineering scope, there is no such thing as infinitely repeating. but in mathematics, there is. in engineering and physics and alot of other applied math fields, precision actually matters. in pure math, 1=1.0=1.00=1.00000000 but in engineering, we know those are completely different.

Someone has finally said something in this thread that makes sense.

[krystar]

Originally Posted by romad

The WHOLE internet can not make a conclusion. Has nothing to do with the education system. They sell t-shirts with the equation on it as a question mark. Its a flawed equation. Its has been for years. Just like writing a bad sentence. 2 is no more correct than 288

i also find interesting what this thread has brought up. in this thread and every other one, both sides have called upon either anecdotal evidence in form of "this person who i trust in math says it's ___" or computerized implementation evidence in form of "my ti-85 says its ____" or "this website says its _____" or "this programming language says its ____"

even the few arguments that have called into order of operations has clearly shown that even the same taught concepts have be interpreted incorrectly.

on the virtual internet, in the absence of math books that clearly spell out unchanging undisputed "the master rule", anyone can post up a webpage that claims that 48/2(9+3)=2 and can make it list high enough on google would have a legitimate shot of convincing other people that it IS in fact the truth. will it be really the future where the mob induced "truth" becomes the real truth?

according to our rennlist poll, the answer should be 2 by a factor of basically 3:2. if the margin were even wider...say 10:1, would it be possible that 2 be made the correct answer? are things like this up for democratic vote?

[romad]

There is no indications that someone is claiming the final solution. In fact its very clear across the INTERNET that this is not solvable. With out knowing the intent of the equation there is no way of proving the equation.

[krystar]

....i guess it hasn't been clear. i claim finally that 288 is the answer.

the equation is easy to misinterpret however it is not ambiguous, it is not badly written, it is not undefined. incorrect application of the laws of order of operations will yield the incorrect answer. it's as simple as that.

[wdfifteen]

Originally Posted by krystar

i also find interesting what this thread has brought up. in this thread and every other one, both sides have called upon either anecdotal evidence in form of "this person who i trust in math says it's ___" or computerized implementation evidence in form of "my ti-85 says its ____" or "this website says its _____" or "this programming language says its ____"

even the few arguments that have called into order of operations has clearly shown that even the same taught concepts have be interpreted incorrectly.

on the virtual internet, in the absence of math books that clearly spell out unchanging undisputed "the master rule", anyone can post up a webpage that claims that 48/2(9+3)=2 and can make it list high enough on google would have a legitimate shot of convincing other people that it IS in fact the truth. will it be really the future where the mob induced "truth" becomes the real truth?

according to our rennlist poll, the answer should be 2 by a factor of basically 3:2. if the margin were even wider...say 10:1, would it be possible that 2 be made the correct answer? are things like this up for democratic vote?

The rules are arbitrary. We could do a poll on how to spell "check" in English. (check or cheque?). We would be arguing about arbitrary decisions accepted as "correct" by two different cultures and could argue endlessly. It's the same with this problem. The technical world accepts the rule that the 2 operates on the parenthetical term before the division. That's the way we do it. Someone else uses different rules.
The lesson I get from this thread is when you try to work across cultures, you can't simply use your own conventions, you have to be more explicit.

[AirKuhl]

Originally Posted by wdfifteen

I was asking about 1/3 = .3333 .....

I studied engineering, not goofy math problems.
.333 .... is a repeating decimal approximation of 1/3. Every time you use it in a calculation you introduce a rounding error, which you MUST be aware of if you are designing something (like a bridge). You illustrated this in your post when you got the answer 1=.999 ....
It is better to use the rational relationship as much as possible because it is accurate and the decimal is an approximation.

Actually, per the rules of convergence 0.333...repeating equals exactly 1/3. It's only an approximation when you intentionally use less than an infinite number of threes. Yes, I realize (as an engineer myself) that in the real world that's exactly what you have to do. But we're talking about math here.

Originally Posted by romad

There is no indications that someone is claiming the final solution. In fact its very clear across the INTERNET that this is not solvable. With out knowing the intent of the equation there is no way of proving the equation.

Exactly. Actually this is a very precise scientific experiment. Except the experiment isn't a math equation, it's sociology. "Let's create an intentionally ambiguous equation and see how people interact when they inevitably disagree about the answer."

[krystar]

but we're not talking about two different languages (american english vs brit english). the language of mathematics has well defined laws that are NOT arbitrary. 1+1=2 in america is still 1+1=2 in russia is still 1+1=2 in zimbabwe.

if you're saying that in the realm of engineering, A/B(C+D)=A/(B(C+D)) [i.e. B and C+D are in the denominator], I would really begin to question the engineering professor that taught you that, since your math professor would not have taught you that. (not that anyone would be learning order of operations in college)

everyone is drawing upon what their interpretation of the laws of mathematics are. yet we've had little backing from an authoritative party. even as I'm arguing that the answer is 288, my credibility as a math whiz is not proven to you, because I haven't shown you anything other than words and banter to prove that my interpretation of the laws of mathematics is the correct. i may be quoting the right laws but applying them wrong.

unless some accredited math and engineering professors stands up and declares "the answer is _____", us commonfolk will never agree because neither of us accept each other as experts.


*waiting for math/engineering profs to post* heh

[AirKuhl]

Originally Posted by krystar

the equation is easy to misinterpret however it is not ambiguous

Umm.....read this carefully.