48/2(9+3)
 

Curious about Graalians' take on this. Every forum I've asked this on (6Theory, HackForums, Head-Fi) has been split around 50/50.

Solve the equation.

9+3= 12
48/2= 24
24x12= 288

hmmmm. 2.

Poll added.

48÷2(9+3) = ?

48 / (2*9 + 2*3) = ?
48 / (18 + 6) = ?
48 / 24 = 2

At least, that's how I remember it in math, but I always had a hard time with the subject. But as far as I know, distributive property and order of operations plays a key part in a problem like this.

Order of operations people. It's 2. You distribute the parentheses first, making it 42/24. Which is 2. I don't see how this is controversial.

I don't see why you would distribute if you're following order of operation.
@Pimpsy Order of operations doesn't tell you to distribute.

Because parentheses allways come first?

Here's how I solved it.

48÷2(9+3) = ?
48÷2(12) = ?
24(12) = ?
288

@Pimpsy: its so controversial around the internet due to people around the world being taught different order of operation methods. Some people stay strict to PEMDAS and do it in that order, which leads to an answer of 2. Other people follow another version of PEMDAS which states the operations in the groupings MD and AS have no precedence over each other, and should be taken out left to right. That method will lead you to 288.

That's why I'm so curious on everyone's take. Please vote in the poll everyone.

PLEASE EXCUSE MY DEAR AUNT SALLY! Or whatever nursery rhyme they taught you in math class. Yes, PEMDAS like you said ^

It's not controversial, you did it wrong still. 48/2(12) still has 2*12 as the dominating factor. Your other version is incorrect. Multiplication allways takes dominance, you can't have two different answers, that's a fact.

But why is 2*12 still the dominating factor?

Oh I remember in 5th grade they told us
P.E.M.D.A.S
Please Excuse My Dear Aunt Sally (LOL)
Parentheses Exponents Multiply Divide Add Subtract=PEMDAS.

Now breaking down the equation
48÷2(9+3)
First add whats in the parentheses. Your equation should look like this.
48÷2(12)
Now Divide. Equation should look like this.
24(12)
Multiply.
288 is the answer.

PEMDAS M>D. Thats it. Theres no alternate version that favors left to right since that would result in multiple impossible answers like this. End of thread. The answer is two.

I was taught differently, that M=D and should be done in chronological order. Matlab and Python both output 288, a Texas calculator I own outputs 2, but another revision of the same Texas calculator outputs 288.

It has to be 288. It's how PEMDAS works.

288, accidentally clicked 2. :(

@Talon: I was taught that it doesn't matter which comes first, multiply or division but normally the thing that comes first is done first.

Yes, that's what I was taught as well.

(48/2)*(9+3)

24*12

288.

That makes more sense, i guess the tricky part is how strangely the equation is put together. Usually people dont structure equations like that. Like this it doesnt have controversy over order of operations.

I was taught order of operations in 5th grade lol

But the 2 isn't inside the parentheses.

Even if you put multiplication and division on the same tier and treat them chronologically, parenthesis and exponents always come first. The entire purpose of parenthesis is to let the person know to do that portion first. Though distribution is vague in its place in order of operations that we're all taught(PEMDAS), I was always taught to distribute first and I'm pretty sure that is also a very fundamental aspect of algebra.

Some people think that juxtaposition of parentheses takes precedence over the MD operations because its still grouped in a set of parentheses, rather than a multiplication operation. I was taught both methods in school by two different teachers, both saying the other was wrong.

Again, this equation is worded very poorly. It makes much more sense structured properly as (48/2)*(9+3)

But the thing is that the (9+3) parenthesis operation was already done, and now its just grouped in a set of parentheses as a multiplication op. That's what I was taught, anyway.

I was taught that you always distribute before solving the contents of a parenthesis. I imagine in more complex algebra you're gonna have a rough time if you don't distribute first.

Well this problem was probably a example for a certain method.

Worded like (48/2)*(9+3) it adds up to 288. Worded like 48/2(9+3) makes you wonder if you are supposed to do the distribution, but you should not because there is already a 48 being divided from it and you need to do that first before you distribute the two. Because of this it is it should be worded like (48/2)*(9+3), which is 24(9+3) = 288

Well, here are the three ways different people have computed it.

Also, a poll screencapped from PhysicsForums.

http://i.imgur.com/i3JxN.png

Pimpsy is right, its 2.

What is PEDMAS? I was taught BODMAS at school...

BODMAS is the kiddy version of PEMDAS, which stands for Parenthesis, exponents, division, multiplication, addition, subtraction.

Multiplication and division are equal priority and so are subtraction and addition, they should be done left to right. If you think otherwise, blame your education system. It's okay.

Dragonrider did it perfectly in the first reply. As for why you wouldn't distribute, the 2*12 comes after the 48/2. That's multiplication, not parenthesis/exponents. /thread

Exactly. That's what I was taught, and what I believe is correct.

2. I got 2

Explain how?

In my maths class, I asked people 1+1+1*0=? and it made me sad how many people got it wrong.

I asked my friend this problem and he got 145. What the hell.

I got 288.
48/2(9+3)
Do the math in the parentheses first and you get 48/2(12)
Then this reads as 48 / 2 * 12 and you just work left to right to get 288.
I think the whole idea of distributing the number before the parentheses is when you are trying to solve for an unknown variable.

What. 144 would be almost understandable, but...

I guess you could get 144 by misreading and subtracting the 3 from the 9 instead of adding, but where the hell does the extra 1 come from? Last I checked 4*6 doesn't end in 5. How could you mess that up in your HS senior year? He said both times he did the equation, that was his outcome.

Google Calculator
Wolfram Alpha

You do whats inside the parenthesis first...don't distribute just because its a parenthesis.
In this case the parentheses are just used as a grouping symbol.

48 / 2 * (9 + 3)
48 / 2 * 12

And then multiplication and division is on the same level so you work from left to right.

Its not controversial or weird. It's simple math. lol

Just inputted the equation in C# and Perl calculators, they both spat out 288. Interestingly enough, a Casio calculator my dad uses outputted 2.

Traditional calculators don't use Order of Operations.

It's a scientific calculator, so I think it does. Some calculators output 288, some 2. Strange.

Another reason I think this equation is so debated isn't just the argument of operation precedence, but also the notation as well. People (and apparently some textbooks) that receive 2 argue that implied multiplication takes precedence over the basic MDAS operations. An example of implied multiplication would be x(y) or xy, which in our case is 2(9+3). I still stand by 288, though...

Going to ring up my dad's friend who's a teacher at a local math camp.

Theres 2 answers. Both are equally mathmatically correct

You can argue both sides indefinitely but its either 288, or 2.

I'm gonna troll an online math tutor with this ;)

Post results ;D

I use BODMAS. They're exactly the same, I think.

Brackets Over Divide Mulitply Add Subtract. Or I'm talking about something completely different to your problem.

What was your outcome?