|
On April 08 2011 07:30 Torte de Lini wrote: (48÷2)(9+3))
Here you go, this should help solve issues. Do what's on the inside first (9+3) then (48/2) then multiply. ERROR: Unmatched parenthesis.
|
Ah, usually in shorthand typing when you group things like this (1/2x) the 2x is meant to be one variable of the equation. This isn't a test of how smart you are, this is a test of what typing conventions you're used to seeing. For example, to get 288 I would have typed 48/2*(9+3).
By leaving no space there you imply to many (especially with how ambiguous non-equation format type can be) that 2(9+3) is one variable.
Edit: yeah, yeah PEMDAS/PEDMAS but with type format things become confusing very quickly. It's best to group things by variable and use all equation identifiers: (),+,_,*,/ at each decision point.
|
1st one is 288, im shocked so many people picked 2. For the second one I picked (1/2)*x but its down by so many votes its making me a bit confused o_O
EDIT: oh wait is it supposed to be a fraction or division.. That totally changes everything xD
|
On April 08 2011 07:28 darmousseh wrote:Show nested quote +On April 08 2011 07:24 munchmunch wrote:On April 08 2011 07:21 RoyalCheese wrote:I made a couple of experiments in the Maple (math software we use) and there are some interesting results. Perheps there should have been a 24 option in the pool :D http://dl.dropbox.com/u/198399/tl_math_problem.png Woah, what fucked up version of maple is that??? Ok, I just did some experiments, and I realized what is going on there. Maple should really be giving an error, but it is actually evaluating 48 / 2 to 24, and then treating 24 as a function. You see, 24 is the function that returns 24 on all arguments. Weird... Maple assumes that if you don't write the operator, then you want to multiply those parameters. In maple 24/12*(9+3) means (24/12)*(9+3) 24/12(9+3) means (24)/(12*(9+3)) it's this way because humans mistakingly write 1/(2x) as 1/2x. Maple assumes that all humans make this mistake and thus interprets it this way.
I don't think that's what's going on here. See, writing 1/2x gives an error. Writing 48 / 2 (3+9) doesn't do the multiplication with weird priority to get 2, it gives 24, so the factor of (3+9) is ignored. As I wrote in my post, this syntax is actually triggering maple's function evaluation rules.
Edit: On rereading your post, I realize there is a possibility that you meant to troll me by changing the numbers. If so, nice one
|
On April 08 2011 06:51 eLiE wrote:BEDMAS!!! No uni courses necessary here! Show nested quote +On April 08 2011 06:48 hugman wrote:If I saw it written on a chalkboard I wouldn't hesitate for a second, but when I see it written online I get doubts about the writer's intent. If you assume that someone asking for math advice knows how to express divisions properly then you're going to misread their intentions half the time. On April 08 2011 06:46 Unhallowed wrote: This is so far from university math... it is just the application of that BEDMAS rule. I believe this was taught to me in elementary school. What the hell is up with giving everything in math stupid names over in NA? I don't get it. So many named rules for everything, it just seems to promote memorization over understanding. lol, what are you talking about? Anagrams are convenient and there's nothing to understand here; you just have to know the order of operations. Brackets, Exponents, Division/Multiplication, Addition/Subtraction. Easy! No need to be an angry face. Anagram I don't think it is what you think it is
|
I love how 2nd part of this thread is way more appealing to me then most of the SC based threads on TL. Perhaps because there is no balance in math.
|
To all those who are arguing with context or ambiguity against a definitive answer of 288: Taken *this* context here, written as it is, there is only 288 as answers, since the normal order of operators kicks in (btw. I find those BEDMAS/... acronyms quite misleading…). Of course, having had higher math courses, I know notation can be more relaxed, though you usually have indicators what is meant, e.g. it might be written as "1 ∕ 2x" (note the larger spacing, and a larger than normal slash, putting implied parenthesis around 2x) when not enough space for a proper fraction. But this thread is neither a scientific paper, or a higher math course.
|
I didn't see anything tricky at this first... but when I figured it out holy shit it tricks the fuck out of your mind lol! Good thing I didn't fall for it.
This was fun though hahaha.
|
On April 08 2011 07:32 RoyalCheese wrote: I love how 2nd part of this thread is way more appealing to me then most of the SC based threads on TL. Perhaps because there is no balance in math.
Algebra is imba. Most math revolves around it. NERD RAGE!!!!!!!!!
|
On April 08 2011 07:32 RoyalCheese wrote: I love how 2nd part of this thread is way more appealing to me then most of the SC based threads on TL. Perhaps because there is no balance in math.
Oh, there is balance in math. Non-standard analysis is totally IMBA, for example.
|
On April 08 2011 07:22 micronesia wrote:Show nested quote +On April 08 2011 07:20 Helios.Star wrote:On April 08 2011 05:36 N3rV[Green] wrote: ......I'm speechless....dumbfounded, and concerned about the general population that much more.
it's 288. Division and multiplication are equal in priority so it is read left to right.
48/2*(12)
24*12=288
WTF are people thinking.
Its easy to mess up if you do PEMDAS, especially if youve been focusing on higher level stuff for a while. I love all the people in here who got it right, or wrong lol, and are like "OMG ALL OF YOUR MATH SKILLZ SUCKZ!". Ive taken probably about 10 calculus based math courses and having to remember all the algebra rules is by far the hardest part. I really don't think for most people advanced in math the issue should be being able to remember the rules of order of operation... it's just a matter of what is more natural for them based on how the expression is written. That's not to say people with degrees in math can't forget basic math but I don't think that's a predominant issue in this thread among the well educated in math.
Im getting my math degree at U of Michigan and thats the first time I've seen numbers written like that in YEARS without an unknown variable. To me it just looks....weird for some reason. If one of the numbers in there was substitited for an x or y I wouldnt have had to think about it at all, but because of how its written I had to go back to elementary school in my head and say the rules to myself. Honestly if I got to the end of a problem and ended up with numbers like that I would just backtrack to the nearest variable and plug it in to solve it that way.
|
On April 08 2011 07:30 Myles wrote:Show nested quote +On April 08 2011 07:26 Mailing wrote:On April 08 2011 07:23 koreasilver wrote:On April 08 2011 07:18 Mailing wrote: I always learned even up through Uni that
48÷2(12)
It would be WRONG to treat this as 24 x 12
That you should always distribute to 48 / 24 FIRST.
If you do 48÷2(12x), it is incorrect always to go 24(12x), and you must do 48/(24x)
Is this not always the proper approach? What they're saying is that technically this is wrong because technically 48÷2(12) is no different from 48 ÷ 2 x 12. But in our mathematics classes it has always been that we would interpret the notation as you have, and that this was just a given. So in conventional use it would be 2, but technically it is 288. I learned that it is mathematical law(?) that you distribute always after parenthesis 48÷2(9+3) is essentially 48 / (18 + 6), but it is far more simple to do 48÷2(12) first THEN distribute to 48÷24 The other way people have been getting 288 is just mathematically incorrect, regardless of interpretation, from what I learned.... Am I wrong or does everywhere else teach math wrong? o_0 You're distributing wrong. Because it's multiplication or division, you distribute both the 48 and the 2. It would go to (48÷2)*9+(48÷2)*3. If it were 48+2(9+3) then it would go to 48+(18+6)
That's assuming 48 * (9+3) 2
Or you can assume 48 2(9+3)
The more I think about it the more it's just really poor formatting.
|
The body builder thread is pure gold, I havent been able to stop laughing since i started reading and im 45 pages deep right now
|
The most interesting thing about this thread are actually the results of polls 1 and 3 together. Most people voted 288 as result but at the same time voted for the interpretation that gives 2 as result. Doesn't make any sense...
|
I read 48÷2(9+3) as 48/2*(9+3) = 24*12 = 288
I can see why people who memorised PEMDAS would get a different result since the abbreviation doesn't remind you that multiplication and division rank equally.
I find 1/2x more ambiguous. I'd probably read it as a lazy (1/2)x unless I spent a lot of time writing math equations on one line. Reading it as 1/(2x) and using 0,5x for (1/2)x would probably be more common if you spend any decent amount of time typing lots of equations.
I say we just insist on people using appropriate/clarifying parentheses when typing math on a single line.
|
Honestly I'm most astonished by the fact that anyone has strong opinions about the correct answer and the ability of your average person. This shit is so absolutely irrelevant and says nothing about someone's skill in math.
Basically the only reason it ever matters is when you're trying to get a calculator or computer to give you the right answer. Otherwise who cares?
|
On April 08 2011 07:26 Mailing wrote:Show nested quote +On April 08 2011 07:23 koreasilver wrote:On April 08 2011 07:18 Mailing wrote: I always learned even up through Uni that
48÷2(12)
It would be WRONG to treat this as 24 x 12
That you should always distribute to 48 / 24 FIRST.
If you do 48÷2(12x), it is incorrect always to go 24(12x), and you must do 48/(24x)
Is this not always the proper approach? What they're saying is that technically this is wrong because technically 48÷2(12) is no different from 48 ÷ 2 x 12. But in our mathematics classes it has always been that we would interpret the notation as you have, and that this was just a given. So in conventional use it would be 2, but technically it is 288. I learned that it is mathematical law(?) that you distribute always after parenthesis 48÷2(9+3) is essentially 48 / (18 + 6), but it is far more simple to do 48÷2(12) first THEN distribute to 48÷24 The other way people have been getting 288 is just mathematically incorrect, regardless of interpretation, from what I learned.... Am I wrong or does everywhere else teach math wrong? o_0 You're reading the question wrong. It's actually: 48 * (1/2) * (9 + 3). Distributing 0.5(9+3) will work fine.
|
On April 08 2011 07:13 iCCup.Raelcun wrote: The only people who are dropping my jaw in this thread are the people who are refusing to acknowledge that it's a trick because of multiple ways of interpretation.
No reasonable person would write the problem like that, but rules exist to tell you how to read it; it's not a matter of choosing between equally valid interpretations.
|
I always learned that the P in PEMDAS means inside the parentheses, and nothing beyond that (and a quick google search confirms). I'm glad I'm learning math the right way ^_^
EDIT: Oh, and PEMDAS should really be written P/E/MD/AS, to avoid confusion.
By the way, 1/2x has absolutely no ambiguity. It's definitely x/2; the 1/(2x) is a misconception, and 1/2x should actually never be written as a substitute for it.
It's acceptable to write 1/(2x) with 1 above BOTH the 2 AND the X below the line, but not 1/2x. It literally means "1 divided by 2 times x". The words "the quantity" are so underused in life XD
|
|
|
|
|