48/2(9+3)
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48/2(9+3)
#1 
by Skyforger » Apr 13, 2011 6:47 am
Ok, so this has become the latest internet meme, am I total fucktard for thinking it equals 288?
My solution:
48/2(9+3)
= 48/2(12)
= 24(12)
= 288
My friend is trying to argue that it should go this way:
48/2(9+3)
= 48/2(12)
= 48/24
= 2
Who is right?
We argued at the bar tonight for 3 hours...
My solution:
48/2(9+3)
= 48/2(12)
= 24(12)
= 288
My friend is trying to argue that it should go this way:
48/2(9+3)
= 48/2(12)
= 48/24
= 2
Who is right?
We argued at the bar tonight for 3 hours...
Last edited by Skyforger on Apr 13, 2011 7:03 am, edited 1 time in total.
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Re: 48/2(9+3)
#2 by 95Theses » Apr 13, 2011 7:02 am
brackets, multiply, divide, add
it's lacking a set of brackets when written like that to make it clear if it means 48/(2((9+3)= 48/(24) = 2 or if it means (48(9+3))/2 = (576)/2 = 288
This, of course, is why we don't write math like that, if you tried to write it properly then it would be instantly clear which way you meant it.
According to the way Excel works, it is 288, but that is because Excel assumes it means (48/2)*(9+3)
it's lacking a set of brackets when written like that to make it clear if it means 48/(2((9+3)= 48/(24) = 2 or if it means (48(9+3))/2 = (576)/2 = 288
This, of course, is why we don't write math like that, if you tried to write it properly then it would be instantly clear which way you meant it.
According to the way Excel works, it is 288, but that is because Excel assumes it means (48/2)*(9+3)
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Re: 48/2(9+3)
#3 by Skyforger » Apr 13, 2011 7:07 am
So when it is written this way it could mean either?
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Re: 48/2(9+3)
#4 by LucidFlight » Apr 13, 2011 7:08 am
As it is written, and according to standard precedence rules, 288 is correct... I think. 
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Re: 48/2(9+3)
#5 by natselrox » Apr 13, 2011 7:08 am
2 acc. to BODMAS.
Depends on the rule one uses.
Depends on the rule one uses.
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Re: 48/2(9+3)
#6 by LucidFlight » Apr 13, 2011 7:13 am
If it were written thusly, it might be a different matter:
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Re: 48/2(9+3)
#7 by Thommo » Apr 13, 2011 7:14 am
95 sums it up well.
Strictly speaking the expression is syntactically incorrect, symbols are missing that would make it a correct formula. We do this kind of thing all the time (excluding all sorts of brackets that would appear in a formalism) because it doesn't render any ambiguity, but in this case it does, so it becomes a matter of seeking clarification from the person who wrote it as to what was intended, or a matter of convention.
The standard convention is BODMAS:
http://www.mathsisfun.com/operation-order-bodmas.html
http://en.wikipedia.org/wiki/Order_of_operations
This convention would give the answer as 288.
ETA: Aww, look at all the people that submitted ahead of me while I was making my coffee. No fair.
Strictly speaking the expression is syntactically incorrect, symbols are missing that would make it a correct formula. We do this kind of thing all the time (excluding all sorts of brackets that would appear in a formalism) because it doesn't render any ambiguity, but in this case it does, so it becomes a matter of seeking clarification from the person who wrote it as to what was intended, or a matter of convention.
The standard convention is BODMAS:
http://www.mathsisfun.com/operation-order-bodmas.html
http://en.wikipedia.org/wiki/Order_of_operations
This convention would give the answer as 288.
ETA: Aww, look at all the people that submitted ahead of me while I was making my coffee. No fair.
Everything in moderation, even moderation.
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Re: 48/2(9+3)
#8 by LucidFlight » Apr 13, 2011 7:20 am
Yeah, it's 2...
(Geez I'm rusty.)
No... wait... 288. Argh!!!
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Re: 48/2(9+3)
#11 by LucidFlight » Apr 13, 2011 7:26 am
Skyforger wrote:So in conclusion, "FUUUUUUUUUUUU!"?
Something like that. It's ambiguous due to the formatting, as 95 and Thommo have suggested.
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Re: 48/2(9+3)
#12 by Skyforger » Apr 13, 2011 7:49 am
See I don't think the formating is ambiguous:
You don't multiply 2(12) before 48/2, even if the 12 is in brackets, because 48/2(12) is the same as 48/2*12, the brackets are meaningless (as far as order of operations) once we've already solved what is in them. Is that wrong?
It seems to me that the only way the answer is 2 is if the 2(12) operation calculates before the 48/2, and that doesn't make sense to me. We should be calculating left to right? Since it is a matter of multiplication and division, when they are together you read left to right, and even though there are brackets, those brackets are only another way of stating multiplication.
Is 8/2(4) not the same as 8/2*4?
You don't multiply 2(12) before 48/2, even if the 12 is in brackets, because 48/2(12) is the same as 48/2*12, the brackets are meaningless (as far as order of operations) once we've already solved what is in them. Is that wrong?
It seems to me that the only way the answer is 2 is if the 2(12) operation calculates before the 48/2, and that doesn't make sense to me. We should be calculating left to right? Since it is a matter of multiplication and division, when they are together you read left to right, and even though there are brackets, those brackets are only another way of stating multiplication.
Is 8/2(4) not the same as 8/2*4?
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Re: 48/2(9+3)
#13 by 95Theses » Apr 13, 2011 7:57 am
Yes but again, you are omitting brackets that should be used to indicate whether you mean (48/2)*12 OR 48/(2*12)
We are agreed that once the brackets have been solved they can be discarded, but that doesn't alter the fact that there is still a set missing to indicate which of the two options above you mean.
ETA: the correct answer to your friend would be 'It could be either until you properly format the equation, please explain where the brackets should go'
We are agreed that once the brackets have been solved they can be discarded, but that doesn't alter the fact that there is still a set missing to indicate which of the two options above you mean.
ETA: the correct answer to your friend would be 'It could be either until you properly format the equation, please explain where the brackets should go'
The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts - Bertrand Russel
Quoting yourself in your own signature is both narcissistic and plain weird - 95Theses
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Re: 48/2(9+3)
#14 by Thommo » Apr 13, 2011 8:01 am
Skyforger wrote:We should be calculating left to right?
Yes, but it's a matter of convention.
In a way it's no more correct that writing left to right - it's correct in English, because that's the convention English adopted. It's not correct in all other languages though.
Everything in moderation, even moderation.
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Re: 48/2(9+3)
#15 by Skyforger » Apr 13, 2011 8:09 am
I wish it were that simple, but I did not come up with the equation. AFAIK it started on bodybulding.com, maybe 4chan, I don't frequent either, I read it on another forum (siting bodybuilding.com as the source) and my friend brought it up tonight at the bar (saying 4chan was the source), but either way...
I am still caught up on the idea that parentheses are just another way of formating multiplication, which means to me the formating isn't ambiguous. Maybe I am just arguing my point into the ground (which I am likely to do), but I don't see how the other set of parentheses can't be implied, and even if they aren't, I can't see how the parentheses in this equation would multiply with the 2 before the 2 divides the 48.
I am still caught up on the idea that parentheses are just another way of formating multiplication, which means to me the formating isn't ambiguous. Maybe I am just arguing my point into the ground (which I am likely to do), but I don't see how the other set of parentheses can't be implied, and even if they aren't, I can't see how the parentheses in this equation would multiply with the 2 before the 2 divides the 48.
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Re: 48/2(9+3)
#16 by 95Theses » Apr 13, 2011 8:14 am
The point is that the original equation is missing a set of parentheses which makes it ambiguous, it has nothing to do with what we are doing with the set that are there.
The whole problem with the world is that fools and fanatics are always so certain of themselves, but wiser people so full of doubts - Bertrand Russel
Quoting yourself in your own signature is both narcissistic and plain weird - 95Theses
Quoting yourself in your own signature is both narcissistic and plain weird - 95Theses
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Re: 48/2(9+3)
#17 by Tyrannical » Apr 13, 2011 8:15 am
95Theses wrote:Yes but again, you are omitting brackets that should be used to indicate whether you mean (48/2)*12 OR 48/(2*12)
We are agreed that once the brackets have been solved they can be discarded, but that doesn't alter the fact that there is still a set missing to indicate which of the two options above you mean.
ETA: the correct answer to your friend would be 'It could be either until you properly format the equation, please explain where the brackets should go'
.precedence of rules the follow and, right to left read we because formula the with ambiguous nothing is There
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Re: 48/2(9+3)
#18 by Thommo » Apr 13, 2011 8:20 am
It's simple - it's not ambiguous if you assume that the statement is to be read with the BODMAS convention.
One or other set of parentheses is omitted, as a matter of convention, to make it into a syntactically correct statement they must be implicitly put in. Your point is that you don't find it ambiguous which parentheses belong because you are correctly applying the standard rule we are all taught in school, which is fine, but from a technical point of view (and understanding where others are confused) it's important to acknowledge the insertion of these parentheses.
Clearly someone who has misremembered, misapplied or was never taught that convention might reach another answer - e.g. if they assume that multiplication takes precedence over division, as would appear to be the case in the "BODMAS" acronym.
One or other set of parentheses is omitted, as a matter of convention, to make it into a syntactically correct statement they must be implicitly put in. Your point is that you don't find it ambiguous which parentheses belong because you are correctly applying the standard rule we are all taught in school, which is fine, but from a technical point of view (and understanding where others are confused) it's important to acknowledge the insertion of these parentheses.
Clearly someone who has misremembered, misapplied or was never taught that convention might reach another answer - e.g. if they assume that multiplication takes precedence over division, as would appear to be the case in the "BODMAS" acronym.
Everything in moderation, even moderation.
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Re: 48/2(9+3)
#19 by LucidFlight » Apr 13, 2011 8:24 am
Right, so... what is the correct simple answer? 
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Re: 48/2(9+3)
#20 by Thommo » Apr 13, 2011 8:27 am
- "That statement is not formatted correctly" if you want to be a stickler.
- "288" if you want to assume the expression was correctly written with the intent of being understood under BODMAS.
I would personally ask whoever wrote it to clarify if I saw it, as the statement smacks (subjectively) of exactly the kind of thing people write without methodically thinking through how people will interpret it and could mean either.
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