48÷2(9+3) = ?

[Charles]

48÷2(9+3) = ????

A) 2
B) 288

[Ratbag]

48
..2 ..... (9+3)

or

....48....
2(9+3)

could both be inferred from that statement and each give one of the two answers correctly, similarly with any other problem written that way why do you ask?

[Chachma v'Oz]

The only correct answer as expressed is 288. A divided by B times C is AC/B and nothing else. Additional parentheses would have to be introduced grouping the terms differently to arrive at a different answer.

[SivVulk]

have we forgotten our BEDMAS?

Brackets always have to be taken care of first.. so the last calculation ends up being 48 divided by 24.. does it not?

[Chachma v'Oz]

Brackets have to be taken care of correctly.

[Ratbag]

we have most certainly not forgotten our Bodmas... inside brackets first, giving you 48/2 ( 12) however, you are now left with a multiply and a divide each of which are equal in strength and will give two different answers .....

[Chachma v'Oz]

Only one of which is correct, the way it is expressed. To come up with an answer of "2" you would need to bracket the last two terms as the single term [2(9+3)].

[jwreck]

Multiply before you divide. Please Excuse My Dear Aunt Sally

Parenthesis exponents multiply divide add subtract.

The answer then of course is 2.

[Ratbag]

could be quite right there jwreck I haven't done this since year 6 math, was assuming it was a question in need of answering not a deep and meaningful puzzle

Soooo instead of learning BODMAS all these years would have been better if it'd been BOMDAS?

[SivVulk]

It's really open to interpretation ... if you follow the simple law that when there is confusion over what operation to do first you start from the left and go right you end up with 288. However if you give greater weight to multiplication rules you end up with 2.

And yeah I should have figured this was a meme...

[Lulu]

Only one of which is correct, the way it is expressed. To come up with an answer of "2" you would need to bracket the last two terms as the single term [2(9+3)].

No, not necessary, it's understood. I've had more than my share of statistics within the past year.

Answer = 2

[Chachma v'Oz]

Plug

48÷2(9+3) =

into google.com and look at the single answer it produces.

Arithmetic is not ambiguous but people can be mathematically illiterate.

[Charles]

The correct answer is 288.



The correct sequence is 48 divided by 2 (equals 24) times the sum of 9 and 3 (12) = 24 * 12 = 288.

Don't believe me? Try it in Excel, Matlab, and Google.


Now, the overwhelming majority of people (including mathematicians and engineers) will look at that problem and conclude it is 2 and they'd be wrong. Which makes me wonder, How many designs have failed (after having gone to production) simply because a bunch of designers casually assumed the solution was 2? Wings fall off airplanes due to mistakes such as these.

[Chachma v'Oz]

Nobody manages to become a mathematician or an engineer without basic arithmetic skills.

[olecapt]

This is a well known class of problem that deals with mathematical procedures. There is no right answer. It is ambiguous.

There is a long and glorious literature on this type problem dating back many years.

If you wish your problems solved precisely you must so specify. If not you can enjoy the ambiguous with the rest of us.

Excel by the way has the right answer. It errors out.

For true authority you can go with google who goes with 288. But if you do then you have to always go with google...I don know if you want to do that.

[Lulu]

Well, I'll be go to hell... apparently there's a huge debate over this . I entered 48/2(9+3) into google and got sent to a bunch of math nerd sites.

[SivVulk]

I found a facebook poll where 631 people voted "2" as the correct response and 573 voted "288".

[Charles]

Nobody manages to become a mathematician or an engineer without basic arithmetic skills.

I must be the exception then because when I first saw the problem, I replied 2. When I asked 10 or 15 other engineers and mathematicians they all said 2. You know who said 288? My seventh grade daugther and the 4th grade teacher who lives next door. Kids and teachers know their PEMDAS; we engineers and mathematicians make the poor assumptions and are wrong.

[Charles]

There is no right answer. It is ambiguous.

There is a correct answer (and it is 288) and the problem is not ambiguous.

[olecapt]

Well, I'll be go to hell... apparently there's a huge debate over this . I entered 48/2(9+3) into google and got sent to a bunch of math nerd sites.

It is not a debate. It is simply under specified and therefore ambiguous.

Once spent a half a million dollars on a prototype steel stamping. It was completely checked every way known to man. When delivered it was also wrong hand.

It happens.