48÷2(9+3) = ???

wonderfulname

Well if you're going to keep parroting that line you may as well pick an example where the answer is 42...

Do you understand the difference between how humans and computers process information?

charles_92688

wonderfulname wrote: »

Do you understand the difference between how humans and computers process information?

I don't know if I understand the difference, but that is irrelevant to the math problem in the original post.

charles_92688

event wrote: »

if ye knew the answer, why did you ask the question?

To increase the click count on this website?

Sparks43

wonderfulname wrote: »

Well if you're going to keep parroting that line you may as well pick an example where the answer is 42...

The answer is 42 and always will be


Now whats that damn question:D

D-Generate

Silly question due to the presentation of the questiona as an inline query. If the question were to be posed by someone writing it on a piece of paper the true syntax of the query would be evident as the brackets would either be placed as the numerator or denominator of the operation or adjacent to the division operation altogether.

As much as it pains me to say this, technically the correct answer as per the rules of maths would be 2. However, that being said, I would expect a computer to evaluate it as 244 as it assumes a structure similar to that which someone would write out.

hyperborean

D-Generate wrote: »

Silly question due to the presentation of the questiona as an inline query. If the question were to be posed by someone writing it on a piece of paper the true syntax of the query would be evident as the brackets would either be placed as the numerator or denominator of the operation or adjacent to the division operation altogether.

As much as it pains me to say this, technically the correct answer as per the rules of maths would be 2. However, that being said, I would expect a computer to evaluate it as 244 as it assumes a structure similar to that which someone would write out.

You should throw that computer in the bin,


Its 288, reply and answer

sponsoredwalk

hyperborean wrote: »

You should throw that computer in the bin,


Its 288, reply and answer

Think you were logged into the wrong troll account in responding here...

im invisible

he might have, but it is 288.

do inside brackets first, then multiply/divide from left to right

sponsoredwalk

im invisible wrote: »

he might have, but it is 288.

do inside brackets first, then multiply/divide from left to right

By what law of nature is that the correct procedure to follow?

im invisible

bomdas/ bedmas/ whatever your having yourself

sponsoredwalk

im invisible wrote: »

bomdas/ bedmas/ whatever your having yourself

Lets take what I'm having, where in this list can we justify that only one of the ways is correct?

bnt

If you do this on a computer, you usually have to explicitly insert the * before the brackets - and when you do that there's no ambiguity. Because brackets are first in the BOMDAS order, the natural tendency is to evaluate them first until they're gone. I have two calculators (HP 35s, Casio FX-991ES) that understand the x(y) notation without adding a *, and both also give me 288.

But there's no point getting all dramatic about this. If I was writing that down, I wouldn't allow that ambiguity to occur in the first place.

lestat21

The fact that such a simple question has caused so much confusion on the maths thread made me smile... 48 / 2(9+3) =

Brackets first 9+3 = 12
No indices to worry bout (sorry charles)
Multiplication 12 x 2 = 24
Division 48/24 = 2

the only way you could get 288 is if the division and multiplication operations changed places
48 x 2 /(9+3) = 288

event

charles_92688 wrote: »

To increase the click count on this website?

you're asking a question there again.
Do you not know why you asked the question?

TheBody

Bad maths makes baby Jesus cry!!

im invisible

last edited by lestat21; Today at 20:23. Reason: Math Error

indeed

Miss Lockhart

Despite this being a well-known meme/troll around a long time, it is an interesting question.

I would say 288 according to BEMDAS.

Brackets
Exponents
Multiplication/Division
Addition/Subtraction

Multiplication/Division and Addition/Subtraction have equal priority and should be carried out from left to right.

I think part of the problem is that people seem think that they must follow BEMDAS in that exact order. Note that in many places BEDMAS is taught, reversing the D and M. Doesn't matter because they have equal priority.

As others have said, the whole problem is caused by very poor notation that would not be acceptable in any serious context.

I also see where the "2" people are coming from. In fact I naturally lean to this method because I naturally seem to give priority to implied multiplication such as the 2(12) part. But I overrule that urge because I have been taught to follow the order of operations a certain way.

Pembily

sponsoredwalk wrote: »

Think you were logged into the wrong troll account in responding here...

Please keep on topic and if you have an issue with a post report the post, don't make assumptions on posters.

Yakuza

48÷2(9+3)

Re-writing with the implied multiplication before the brackets:
48÷2x(9+3)

Resolve the term in the brackets:
48÷2x(12) = 48÷2x12

These are equivalent as multiplication is commutative:
48÷2x12 = 12x48x÷2

No matter what way you cut it, the answer is 288.
The only way the answer could be 2 would be if the original formula was written as:
48÷(2(9+3)).

As stated previously BODMAS dictates how these things are calculated, any deviations from this are, well, deviant!

charles_92688

lestat21 wrote: »

The fact that such a simple question has caused so much confusion on the maths thread made me smile... 48 / 2(9+3) =

Brackets first 9+3 = 12
No indices to worry bout (sorry charles)
Multiplication 12 x 2 = 24
Division 48/24 = 2

the only way you could get 288 is if the division and multiplication operations changed places
48 x 2 /(9+3) = 288

Yes, 9 + 3 = 12 so you're left with

48÷2*12

At this point the correct (and there is only one "correct") operation is to divide 48 by 2 then multiply by 12 which turns into 24*12 = 288. There is no other way to approach this. It is not ambiguous. It is not open to interpretation.

Those who try to weasel word it into an answer of 2 by claiming something about humans and computers "thinking" differently or "it would be nice if there were extra brackets" or "nobody would ever write it that way" are wrong.

The correct answer is 288.

PaulieBoy

Can I have a drum roll please ...... The answer is -according to my TI-89 Titanium, the most powerful calculator in the world and could blow the head off an equation at fifty paces- is 288 :-)

Woohoo, now we can move on .......

CJC86

charles_92688 wrote: »

At this point the correct (and there is only one "correct") operation is to divide 48 by 2 then multiply by 12 which turns into 24*12 = 288. There is no other way to approach this. It is not ambiguous. It is not open to interpretation.

Yes, it is ambiguous. Yes, it is open to interpretation. BOMDAS (or PEDMAS) was only ever introduced to make teaching Maths easier. There is no de facto "order" in which to perform any of these operations, just a convention which generally makes things look nicer on paper. The convention when facing several operations which are of equal precedence would be to go from left to right, but it is not the only "correct" way.

This formula, as with a few others on the internet, is intentionally ambiguous, and hence is just plain bad maths.

Delphi91

Hmm, have to say I was pleasantly surprised by this little conundrum.

Ok, I think everyone is agreed that the part in brackets is done first, so we get

[LATEX]48 \div 2(9 + 3) = $$ 48 \div 2(12) $$[/LATEX]

or effectively

[LATEX]48 \div 2 \times 12[/LATEX]

The rules of precedence for operations show that multiplication and division both have the same priority, so when you get down to an equation with both, then work left to right.

[LATEX]48 \div 2 \times 12 = \frac{48}{2} \times 12[/LATEX]

which gives

[LATEX]24 \times 12 = 288[/LATEX]

moon2

The convention when facing several operations which are of equal precedence would be to go from left to right, but it is not the only "correct" way.

It's only convention that says that multiplication/division happens before addition/subtraction. If you want to ignore the left to right convention, you may as well ignore BOMDAS/whatever as they do go hand in hand. Left to right ensures that every equation has exactly 1 possible way to solve when applying the rules of BOMDAS.

hivizman

I agree with Charles 92688 that, if we apply the standard conventions of arithmetic, and read the expression as if the "/" operator comes between "48" and "2" alone, that there is an implicit "*" operator between "2" and "(9+3)", and there are no implicit brackets around "48/2" or "2(9+3)", the answer to 48/2(9+3) is 288.

But it's interesting to compare this with the Ring around the world thread. In post #3, Eathrin suggested that the answer to the question posed in that thread was "3/2pi feet", to which Charles, in post #5 replied "Yep". But, if we follow the case in this thread, shouldn't we read this as 3/2*pi, and work this out from left to right to get, approximately, 1.5*3.1416 = 4.7124?

In post #9, Charles quite properly expresses this (in inches rather than feet) as "36/(2*pi)", avoiding any danger that readers will misinterpret the expression.

equivariant

Miss Lockhart wrote: »

Despite this being a well-known meme/troll around a long time, it is an interesting question.

....

Its really not

Kavrocks

charles_92688 wrote: »

The correct answer is 288.

To the question in the thread title I disagree.

After you evaluate what is inside the brackets you add in a multiplication sign to the equation effectively changing the equation and leading to your answer of 288.

Also if I type in exactly what you have in the thread title in to my calculator I get 2.

48/2(9+3) = 2 and 48/2*(9+3) = 288

Both are two totally different equations in my opinion.

seamus

BOMDAS implies that you do multiplication before division and addition before subtraction.

This is not the case, it's a result of poor teaching. Multiplication and division have equal priority and must be done in the order that they appear in the equation (starting from the left). In this case therefore you divide 48 by 2 before multiplying the answer by 12.

Yes, it's another thing we were all taught incorrectly in school.

BigCon

Not according to this: http://www.mathsisfun.com/operation-order-bodmas.html

Miss Lockhart

equivariant wrote: »

Its really not

Well, that's a matter of opinion really. Why bother posting if you've nothing constructive to add?

seamus wrote: »

BOMDAS implies that you do multiplication before division and addition before subtraction.

This is not the case, it's a result of poor teaching. Multiplication and division have equal priority and must be done in the order that they appear in the equation (starting from the left). In this case therefore you divide 48 by 2 before multiplying the answer by 12.

Yes, it's another thing we were all taught incorrectly in school.

Maybe you were taught incorrectly but I wasn't.

It's explained very clearly and correctly in school maths textbooks. Perhaps it was taught poorly to a lot of people but I find it hard to believe it was taught incorrectly by that many teachers.

Also, if you google you will see that this question has been debated on many forums for several years by people from many nationalities. Obviously the confusion is not just down to incorrect teaching here in Ireland.