Poll: What is the answer to 48/2(9+3)?

[Eclectic Dreck]

Because multiplication symbol is omitted in math (most of the time) for simplification of writing; same goes in physics

This is true, especially when dealing with variables. xy simply means x*y, x also means x*y. In general, one can link a variable with a constant in this way (3x, or 3*x) but never two constants (33 is interpreted as the number "33" rather than 3*3). 3(3) is, however, acceptable since you have an operand dividing the two that implies multiplication unless otherwise stated.

 

[XandNobody]

Well, it depends.

48
------ = 2
2(9+3)

However,

48/2(9+3) = 288

And you wonder why they always told you to show your work.

 

[robotam]

I read it as i saw it and others saw it. By using 2(9+3) instead of 2*(9+3), it is implying that they are one entity, as in all under the denominator. The confusion isn't in PEMDAS at all, it has to do with how you read the problem.

I agree that this isn't a pedmas problem but rather that people read the question wrong. They assumed that / is saying anything at all about whether something is in a denominator (it's not). Without parentheses it is implied that only the first number is in fact in the denominator, any other expressions after that are seperate.

No the question is deliberatly written in a terrible way, in order to spark arguement between interneters. If you are going to have a division you had better make it clear what is being divided.
You can't just assume they only want to divide by the first number. It is not implied either way. It does look like the 2 on the denominator is being multiplyied by the brackets. And it is impossible to tell which answer is correct.

 

[Juggern4ut20]

I agree that this isn't a pedmas problem but rather that people read the question wrong. They assumed that / is saying anything at all about whether something is in a denominator (it's not). Without parentheses it is implied that only the first number is in fact in the denominator, any other expressions after that are seperate.

While i agree that, you are using an interesting word saying 'implied'. What if the problem was written like this. 48÷2(9+3), would that make it more clear as to what the poster wanted(if that's what the poster actual did want)? I feel a computer reads a problem very literal, where as a human looking at a problem could interpret it different. i dunno that's just my take.

 

[mjc0961]

It's written poorly, but the way it is written it should be done like this:

2... still remember from grade school, Please Excuse My Dear Aunt Sally; Parentheses, Exponent, Multiply, Divide, Addition, Subtract. So... 9+3=12, 12*2=24, 48/24=2.

48/2(9+3)
48/2(12)
48/24 = 2
Nope disregard all that; multiply and division are the same rank, not multiply first, so you go left to right and get 288.
48/2(9+3)
48/2(12)
24(12) = 288

If they wanted the answer to be 2, they should have written the problem like this:
48/(2(9+3))
Which shows that 48 is meant to be divided by everything.

If they wanted the answer to be 288, they should have written it like this:
(48/2)(9+3)
Which shows you divide and add first and then multiply.

Then there would be no confusion.

No the question is deliberatly written in a terrible way, in order to spark arguement between interneters. If you are going to have a division you had better make it clear what is being divided.
You can't just assume they only want to divide by the first number. It is not implied either way. It does look like the 2 on the denominator is being multiplyied by the brackets. And it is impossible to tell which answer is correct.

That's pretty much the size of it, yeah.

 

[ragestreet]

2.

 

[Taerdin]

48÷2(9+3), would that make it more clear as to what the poster wanted?

It would make it more clear to people that don't know that ÷ is equivalent to /.

The expression 48÷2(9+3) is equivalent to 48/2(9+3)

I can only assume people don't know this because they are not familar with doing math on a computer (where we tend to use / in place of ÷ for lack of a ÷ key.)

 

[captain_dalan]

This is only causing a stir because it's poorly written. It isn't clever or some "mind-bender" of a problem. It's just ambiguous. So... who cares?

I'm sorry but generally speaking maths problems can't be ambiguous they follow a set of rules you just need to know the rules.I say generally because I didn't do it at uni and there's quite probably some complicated stuff that comes into it that I know nothing about which could be an exception to that rule.

Yes, but you see, this is not how you'd write this in math, the correct "syntax" would be either:

48
-- * (9+3)
2

or

48
-------
2*(9+3)

 

[somonels]

Approved by the Ministry of Education of the United States of Arabia America.

 

[Taerdin]

No the question is deliberatly written in a terrible way, in order to spark arguement between interneters. If you are going to have a division you had better make it clear what is being divided.
You can't just assume they only want to divide by the first number. It is not implied either way. It does look like the 2 on the denominator is being multiplyied by the brackets. And it is impossible to tell which answer is correct.

I can see how someone who doesn't know how to properly interpret the question might think that it is written in a terrible way. But really there is a specific way to read that statement, and if read properly it will always give the answer 288.

You can just assume that the division symbol means divide only by the first number/expression, what else would it mean? Does 2 * 3 - 4 mean anything other than two times three minus four? Does it mean two times three and two times four? I don't think so. It's a matter of reading the problem properly.

It is very possible to determine the correct answer to a math problem, but I can see how it might be hard for certain people to accept being wrong, especially on an internet forum.

 

[Woem]

I don't know why you want us to do your homework for you, but I got 288... after you do the parentheses, you're supposed to do them from left to right. I think it's a poorly written problem, though.

Mathematics don't care about "left to right". You solve the parentheses first, and then in the order of multiply and divide. The answer is 2. Take it from the European guy.

 

[fulano]

That's actually quite a conundrum.... I'm showing this to my proffesor tomorrow, although I'm pretty sure you're supposed to simplify in the denominator and numerator before dividing, so I end up with 2

If you ask your prof this he will laugh at you.

Simplifying does not change the result.

48/2*12=288
24*12=288

Yeah. Goes both ways, that's the whole point, I guess.

Captcha: Bipeau onsorki...Inglip better be fucking happy...

 

[Juggern4ut20]

It would make it more clear to people that don't know that ÷ is equivalent to /.

The expression 48÷2(9+3) is equivalent to 48/2(9+3)

I can only assume people don't know this because they are not familar with doing math on a computer (where we tend to use / in place of ÷ for lack of a ÷ key.)

Well, duh. of course they are the same thing, but X/2(9+3) makes it look like the 2(9+3) is all under the division. No human would write this out long hand and get confused, its only when dealing with writing it out on a computer (or like device) that there is a misunderstanding. That is why a lot of people tend to get the wrong answers when putting more complex equations into calculators, since there are implied ( ) when writing in long hand.

This looks like a problem that was WRITTEN to have the answer as 2 but when put directly into a calculator the answer was 288. There is no way to tell if that was the case.

 

[Zero_G]

I just signed up to the escapist forums specifically to add two observations here. I'm not going to say what answer i'd get because it honestly doesn't matter. instead, here are two observations:

1) If the confusion comes from the way the problem is written, no calculator or software package is going to give the a certain answer until this has been resolved.

2) Whichever acronym you use, the only decision to be made is if 2(9+3) would be rewritten as one entity as in [2*(9+3)] or two entities as in 2*(9+3). If one, the answer would be 48/[2(9+3)]=2, if two, they could be separated and you could get (48/2)*(9+3)=288 going left to right.

Usually, when typing an equation it is simplified as far as possible to make it easier to write. Leaving out multiplication symbols between numbers and brackets is common, leaving out an entire pair of brackets is unacceptable because it might change the problem. Your answer will depend on point 2 above.

Just to note, I (from the uk) have always used (brackets) [square brackets] and {curly brackets}, with parentheses and brackets being two words meaning the same thing in different situations.

 

[mjc0961]

2... still remember from grade school, Please Excuse My Dear Aunt Sally; Parentheses, Exponent, Multiply, Divide, Addition, Subtract. So... 9+3=12, 12*2=24, 48/24=2.

you remember wrong. you don't solve multiply before divide, they're equal, as are addition and subtraction. that's because dividing is multiplying by a number between 0 and 1 (dividing by 2 is multiplying by 1/2 = 0.5). subtraction same thing, it's addition with a negative number (6 + (-1) = 5)

... *looks*

Yep, you're right. They are the same rank, so you go left to right. That means the answer is 288 if it's written like that. Nice catch.

 

[Bearjing]

I don't know why you want us to do your homework for you, but I got 288... after you do the parentheses, you're supposed to do them from left to right. I think it's a poorly written problem, though.

Mathematics don't care about "left to right". You solve the parentheses first, and then in the order of multiply and divide. The answer is 2. Take it from the European guy.

Didn't realize europeans were bad a math.

 

[PixiePrincess]

It's not an equation. It's an expression, I believe.

There is no "answer" since there is no mathematical question.

 

[Link_to_Future]

But don't you see that at a glance it could be seen the other way? Can't you acknowledge the possibility that someone would just work it in their head real quickly without following that basic rule simply because they failed to see it in that manner?

And I think you have stumbled on precisely why the statement was written as it was. While there is absolutely no ambiguity, the statement is not immediately clear. If one forgoes the process of determining precedence they can easily arrive at the wrong answer. The question was intentionally written in such a way as to invite this very thing.

People aren't wrong or stupid if they get the wrong answer; the only lesson they might take away is that they probably ought to use the rules of precedence when presented with a math problem where the answer actually counts for something save internet points.

I like you.

You can present a point reasonably without coming off as a tool or acting like you're innately superior. I honestly wish more people were capable of that.

I'm going to just continue to argue just for the simple sake of arguing. I hope you don't take it personally, I'm just curious what you think.

How many times are we going to stumble across a problem phrased in this ambiguous of a manner in the real world though? I mean, outside of school work asking explicitly for the answer in this form where is this going to come up?

Perhaps I'm wrong but many careers are either very math intensive or not very much so at all. If the job is math intensive (ie engineering) then the problem your facing is not going to be phrased in such a manner. It's going to be put forward as a set of data and any necessary derivations and formulas needed for use will be done either through hand calculations (my preference) or through computer analysis. Now granted, I can see how this would be an issue with a computer because syntax can be a *****. However,as I stated earlier I'm a fan of ensuring that my equations are not ambiguous. It's just good practice to keep everything neat and tidy with properly placed and closed parenthesis.

As for jobs that aren't math intensive...well, that is pretty self explanatory. If you aren't using math much then an vaguely framed equation is probably not going to pop up.

So I guess the boiled-down question I pose to you is what would a possible real-world situation be where a question framed in this manner would become a hindrance to those not abiding by the strict left-to-right operations?

Again, I'm only arguing for the sake of argument. I'm posing a question for the sake of finding a possible answer. No ill will or anything of that sort.

 

[mjc0961]

It's not an equation. It's an expression, I believe.

There is no "answer" since there is no mathematical question.

Okay. "Simplify 48/2(9+3)."

Better, yes?

 

[UnmotivatedSlacker]

Poorly written problem is poorly written. You haven't specified if it's a fraction or not. If it is, it's 2. If not, the answer is 288.

It's written poorly, but the way it is written it should be done like this:

2... still remember from grade school, Please Excuse My Dear Aunt Sally; Parentheses, Exponent, Multiply, Divide, Addition, Subtract. So... 9+3=12, 12*2=24, 48/24=2.

48/2(9+3)
48/2(12)
48/24 = 2

If they wanted the answer to be 2, they should have written the problem like this:
48/(2(9+3))

If they wanted the answer to be 288, they should have written it like this:
(48/2)(9+3)

Then there would be no confusion. But as it stands, the way it's written means the correct answer must be 2, and if you get 288 then you need to back to basic math and relearn your "please excuse my dear aunt sally".

Wrong good sir. It would go like this:
48/2(9+3)= 48/2(12) =24(12)=288 You always start from the left after taking care of any parentheses and exponents. Don't believe me, put that exact formula on a calculator. I think you need to relearn your "please excuse my dear aunt sally."