You are Here: Home >< Maths

# 48÷2(9+3) = ? watch

• View Poll Results: 48/2(9+3)
2
117
52.47%
288
106
47.53%

1. (Original post by rmhumphries)
Division has precedence normally, I was taught so in Maths, and usually you expect division to have precedence in the 3rd gen languages I have come across (C, C++, Java, etc).
In the field of C, division and multiplication are the same.

Like multiplication by 2, is really division by 1/(1/2).
2. (Original post by rmhumphries)
Division has precedence normally, I was taught so in Maths, and usually you expect division to have precedence in the 3rd gen languages I have come across (C, C++, Java, etc).
C and C++ both have multiplication and division sharing equal precedence. I'd be surprised if Java was any different.

Spoiler:
Show
cf. the C99 standard: footnote 72 ("... Within each major subclause, the operators have the same precedence ...") and subclause 6.5.5 Multiplicative Operators
3. You're right.
Remember the BODMAS rule takes prescendence.
Brackets Of, Division, Multiplication, Adding, Subtracting
So in the case of 48÷2(9+3) it'd be:
(9+3) as the first calculation since it's brackets to give you 12;
2(12) = 24
then finally 48 ÷ 24 (from 2(9+3)) = 2
4. lol
5. (Original post by DanielleT192)
You're right.
Remember the BODMAS rule takes prescendence.
Brackets Of, Division, Multiplication, Adding, Subtracting
So in the case of 48÷2(9+3) it'd be:
(9+3) as the first calculation since it's brackets to give you 12;
2(12) = 24
then finally 48 ÷ 24 (from 2(9+3)) = 2
Your final two lines don't follow the rules of BIDMAS/BODMAS at all. You have multiplied the 12 by 2 before diving.

As much as everyones brain wants it to be 2:

48 ÷ 2(9+3) IS EXACTLY THE SAME AS 48 ÷ 2 x (9+3)

= 48 ÷ 2 x 12
= 24 x 12 (BIDMAS)
= 288

I know, I don't want it to be 288 either, but it's the facts
6. Parentheses
Exponents
Multiplication
Division
Subtraction

48÷2(9+3) = (48/2)(9+3) =(24)(12) = 288
There are "hidden/implied" parentheses around (48/2).

http://www.wolframalpha.com/input/?i=48÷2%289%2B3%29

Its 288.

(Original post by andrewmc96)
My maths teacher taught us that neither had precedence over the other. Oh well, guess he was kinda wrong.
(Original post by Rob da Mop)
I was always taught that division and multiplication (as they are effectively the same thing - 2x0.5=2/2) and addition and subtraction (again, 2-2 = 2+(-2)) are treated equally, so it now goes left to right. Therefore, strictly speaking, I suppose it is 288, but really it's just a poorly written equation.
To be fair, in Maths, I may be wrong, it has been a few years since I did Maths, and I now look at things in a computing view point. If you don't assign a priority in a complier, the complier breaks if it has to make a choice and isn't told what choice to make! The second quote is a fair point as well
8. That isn't the equation as you posted it.

I typed in the equation exactly as in the thread title, and it give the answer as 288.

Surely the way you typed the equation there isn't equivalent to the thread title equation, seeing as they both give different answers.

9. or

It may look ambiguous to some, but since the (9+3) is multiplied by the 2 it is safe to assume it goes with the denominator.

10. (Original post by Farmer Giles)

or

It may look ambiguous to some, but since the (9+3) is multiplied by the 2 it is safe to assume it goes with the denominator.

i was about to suggest to write it as a fraction, theres jsut no argument that the answer is 2 and i'm surprised how many people dont get it

ok now i finally see why people get 24*12, but isnt the first thing you learn in maths to multiply out of brackets first?
11. I think we can all safely say that the answer is 56
12. In summary: it depends where you put the brackets
13. I would say 2.

We were taught BOMDAS and also BODMAS.

In my maths class we were told it makes no difference.
14. So, 313?
15. Very interesting question

My Casio fx-9750GII, Casio fx-83ES, MatLab and a programm in C, all give 288
16. and what i dont get is that the maths some people are using here is that it goes from division to multiplication without any reason.
48 / 2(9+3) = 24 * (9+3)... why?? can anyone tell me what this is? why isnt it
= 24/(9+3) = 2 ? wheres the proof that simplification magically changes the operation?
17. (Original post by kaosu_souzousha)
Very interesting question
No wonder the UK is up **** creek without a paddle .... pah
18. depends on how you look at it. this is why brackets are so important.
at first glance, i thought it meant 48/2 x (9+3) so i'm going to say 288.
19. (Original post by Cornish student)
48÷2(9+3) = 288 because the order in BIDMAS infers:

1. Brackets (9+3) = 12
2. Division = 48/2 = 24
3. Multiplication 24*12 = 28

(I, A and S are not part of the equation so I skipped the stages)
No no no no no no no!

Edit: Best thread I've seen in ageeeees.
20. electronics say it is 288

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 9, 2011
Today on TSR

How do you think you'll do?

### University open days

Wed, 25 Jul '18
2. University of Buckingham
Wed, 25 Jul '18
3. Bournemouth University
Wed, 1 Aug '18
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams