Math Hurts: 48÷2(9+3)

[niky]

You've created a monster. This is just going to be like that stupid Airplane on a treadmill question we had years ago.

Second time on two boards I've heard that complaint. Seriously... this one is much more fun.

 

[GTR3mh]

My CAS calculator gave me the answer of 288, and considering there are differences between calculator order of operations, that really supports the answer of both answers being correct.

 

[wfooshee]

Order of operations does not allow for "implicit" order.

Parentheses

Exponents

Multiplication and division

Addition and subtraction

All as encountered left to right

Period

The 2 being on the parentheses does not mean, nor is it even allowed to imply, "do this first."

 

[Azuremen]

Second time on two boards I've heard that complaint. Seriously... this one is much more fun.

No, there is far less to discuss to this one. Engineers and most science people tell you implied multiplication is usually done before the other division and multiplication operations.

Let alone the fact that "÷" is never used beyond maybe algebra. It is just a poorly formulate question, where as the airplane one had at least an remotely interesting physics element that could be analyzed and given a solid answer - that the treadmill didn't matter at all.

 

[Sharky.]

The 2 being on the parentheses does not mean, nor is it even allowed to imply, "do this first."

So do you take 2/5x as written to mean 0.4x or 2/(5x)?

 

[Azuremen]

Order of operations does not allow for "implicit" order.

The majority of people I work with would disagree, and they'd pretty much all write the 2(9+3) under the 48.

 

[niky]

No, there is far less to discuss to this one. Engineers and most science people tell you implied multiplication is usually done before the other division and multiplication operations.

Let alone the fact that "÷" is never used beyond maybe algebra. It is just a poorly formulate question, where as the airplane one had at least an remotely interesting physics element that could be analyzed and given a solid answer - that the treadmill didn't matter at all.

Hey... all that the treadmill myth required was a little common sense. This one represents a fundamental problem with implied multiplication versus textbook mathematics.

 

[Jay]

Hmm I implied multiplication so went with 288, however looking at it again differently... yes it could be 2 also.

 

[ElijahCraig18]

Azuremen does Cobaltnova mean anything to you?

 

[lukecfc]

Write the thing as a fraction, 48 is on top. All of the bottom is in implied brackets
48/(2(9+3)). The answer is 2.

 

[Rossticles]

ibalongassthread

 

[dylansan]

To save this thread some trouble:
The answer is either 2 or 288, with 2 being the more commonly accepted answer.

Even though the two is not in parenthesis/brackets, it's generally multiplied by the 9+3 before division because it's right next to the parenthesis, not separated by a multiplication sign, resulting in an answer of 2. Really though, it's an ambiguous problem whose answer depends on conventions which are different for different people. I personally can't imagine separating the two from the 9+3 to do a different operation first. It just doesn't work in my head, but for some people, it follows all the rules they've learned to use, and they get 288 in the process.

 

[Keef]

48
_____

2(9+3)

=

48
_____

18+6

=

48
__

24

=

2

 

[Carlos]

Becaus it's a ÷ and not a /
So 2 it is.

 

[itsbenjibrand]

Using order of operations, the answer is 288. Therefore 288 is obviously the correct answer. I'm not changing my view on this one, this is the math I'm good at, and excel at, so there's no chance in h:censored: that I'm wrong. 288! ITS 288!👍. Use BEDMAS, do the brackets, 9+3=12, then the division, 48 divided by 2=24, then multiply 24 by 12. 24x12=288.

 

[Villain]

PEMDAS

M is before D.

288.

 

[Azuremen]

PEMDAS

M is before D.

288.

If M is before D, you'd get 2, since you'd complete the 2(12) and then do the division.

 

[Sharky.]

You realise that M before D gives you 2 not 288, right?

(damn you Cody)

 

[Villain]

Actually. Yes I do. But I left it like that because I'm stubborn and had to choose one. I refuse to waffle!

http://www.mathgoodies.com/lessons/vol7/order_operations.html

FWIW, Google says 288.

 

[Keef]

The order of multiplication and division doesn't matter, you simply do them from left to right. The issue here is that ya'll are misunderstanding what division is. It's akin to a grouping symbol, and that's why 288 is wrong. In my previous post I showed every step to doing this problem, which involves grouping the 48 as the numerator and 2(9+3) as the denominator, FOILing the parenthesis, then performing the division.

This problem is so basic I've been arguing with a friend over it for a half hour because I didn't know why division was a grouping symbol.

 

[nk4e]

Please excuse my dear aunt sally.

 

[Villain]

Please execute my dear aunt sally.

/fixed

 

[Keef]

48/2(9+3)

Set to zero.

48/2(9+3)=0

[2(9+3)]48/2(9+3)=0[2(9+3)]

48=0

All of you are wrong. Clearly, forty-eight equals zero.

 

[Villain]

Is it okay if I change my answer to this:

 

[Talon]

48/2(9+3)

Set to zero.

48/2(9+3)=0

[2(9+3)]48/2(9+3)=0[2(9+3)]

48=0

All of you are wrong. Clearly, forty-eight equals zero.

By that logic, you're a zero.

 

[grymey]

For everybody saying 2, what if you write it out as 48*1/2(9+3) , only one answer, 288.

 

[Azuremen]

For everybody saying 2, what if you write it out as 48*1/2(9+3) , only one answer, 288.

Umm, what?

 

[ROAD_DOGG33J]

For everybody saying 2, what if you write it out as 48*1/2(9+3) , only one answer, 288.

Then you shorten it to 48 over 2(9+3) as the denominator.

Umm, what?

Basically turning the division into the corresponding multiplication, I think

 

[Omnis]

The division bar is a grouping tool. 48 is one group and 2(9+3) is another. So the problem should look like (48)/(2(9+3)) = 2.

 

[GTR3mh]

For everybody saying 2, what if you write it out as 48*1/2(9+3) , only one answer, 288.

That's because you've made it into a different yet similar equation. Instead of 48 divided by 2 multiplied by (9+3), you've changed it to 48 multiplied by 0.5 multiplied by (9+3). There is no division in your equation.