48/2(9+3) = ?

[CissNei]

Came across this in a few forums! 288?

EDIT:
Turned out that the title didnt post properly, it should've been (Division sign, in this case not "/")

48 "Division sign" 2(9+3) = ?

[Chelsea]

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

hope i am right
looks logical to me.

[nickvl]

maybe its 48/2 x (9+3)?
= 24 x 12
= 288

[henry_yew]

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

hope i am right
looks logical to me.

maybe its 48/2 x (9+3)?
= 24 x 12
= 288

The answer is 288. Not 2. Here is the explanation:

When you do a mathematical operation like this, the law is to solve whatever is in the bracket first. Once that part is solved, the operation proceeds from left to right as usual, with multiplications and divisions taking priority first before considering additions and subtractions. In this case:

48/2(9+3) = 48/2(12) = 48/2*12 = 24*12 = 288

48/2(12) is simply not the same as 48/[2(12)]. The former will give 288, the latter yields 2.

The point is: do not add brackets or parentheses unnecessarily. Sometimes you might just be making an error when you put a set of extra brackets, or imagine that there is one.

[youngyew]

Came across this in a few forums! 288?

EDIT:
Turned out that the title didnt post properly, it should've been (Division sign, in this case not "/")

48 "Division sign" 2(9+3) = ?
In computer typography usually the slash (/) is used in the same context as the division sign.

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

hope i am right
looks logical to me.

maybe its 48/2 x (9+3)?
= 24 x 12
= 288
If we were to interpret 48/2(9+3) in a casual context, we would be quite tempted to see the 2(9+3) part as a group because 2(9+3) is more seen as "nine plus three doubled" instead of two, times, the sum of nine plus three. So in some ways our mind automatically added brackets around the whole (2(9+3)) even though it wasn't specified in the original phrase.

In strict computation though, we have to obey what is often summarised as the "BODMAS" order in English (Brackets, Other, Division, Multiplication, Addition, Subtraction) - note that Division and Multiplication are on the same tier, so are addition and subtraction. In this case, we should do the addition inside the brackets (which gives us 12), then division of 48/2 (24), and then multiply by 12.

[Chelsea]

yup, i think henry yew is right. i made an error when applying the BODMAS rule when expanding the equation. thanks.
and one question. this symbol [ ] is it called parentheses. noticed that you used it.

[henry_yew]

In strict computation though, we have to obey what is often summarised as the "BODMAS" order in English (Brackets, Other, Division, Multiplication, Addition, Subtraction) - note that Division and Multiplication are on the same tier, so are addition and subtraction. In this case, we should do the addition inside the brackets (which gives us 12), then division of 48/2 (24), then do the 24 * 2, and then multiply by 12.

Tak faham, boss. We should do addition inside the brackets (which gives us 12). OK! Faham. Then division of 48/2, which gives 24. OK! Faham also. Do the 24 * 2? Tak faham lah! :(

[youngyew]

Tak faham, boss. We should do addition inside the brackets (which gives us 12). OK! Faham. Then division of 48/2, which gives 24. OK! Faham also. Do the 24 * 2? Tak faham lah! :(
Sorry I must be half asleep. Corrected it :)

[CissNei]

1/2X where X = 2?

[youngyew]

Huh what are you referring to CissNei?

[henry_yew]

1/2X where X = 2?

Huh what are you referring to CissNei?

I think CissNei is trying to ask why we cannot view the division as a fraction, e.g. ⅜, ⅞, ? etc.

Well, actually the original poster didn't use the "/" symbol to mean "divide by". The original poster actually wanted to denote the conventional "divide by" symbol (the one dash with one dot above it, and one below). Had he written the operation in a fraction form like this:

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

(desperate way of writing fractions in ReCom)

then the answer would have been 2. In the usual way of writing the above fraction, it would be 48/[2(9+3)]. CissNei, your fraction as quoted above, would have been written as 1/(2x).

sin 2x, cos 2x and tan 2x are all understood as sin (2x), cos (2x) and tan (2x). However, sin 2x + 5 is not the same as sin (2x + 5)! The former would have been interpreted as sin (2x) + 5.

Confused? I'm not a mathematician either. Ask one. Haha...

[the_thinker]

try typing 48%2(9+3) in your calculators... some give 2 some give 288

%= divide symbol... i think its just one of the many curiosities of math
lesson is, add more brackets to be precise about what ur calculating... :)

[surayahamdan]

1/2X where X = 2?

1/2X = 1/2*X strictly speaking or http://latex.codecogs.com/gif.latex?1\div&space;2\times&space;x

Don't confuse it with http://i.imgur.com/JCi0X.gif

[youngyew]

1/2X = 1/2*X strictly speaking or http://latex.codecogs.com/gif.latex?1\div&space;2\times&space;x

Don't confuse it with http://i.imgur.com/JCi0X.gif
Again, a casual reader tends to take 1/2x as one over two x, because it's precisely how we would read it as it was written.

However, a strict computer system would simply define any two items put next to each other as a product, and it usually doesn't add any brackets to a statement. Therefore, since there is nothing between 2 and x, and that there wasn't any bracket in the expression 1/2x, a computer system will just interpret it as one, divided by two, multiply by x. In other words, x/2.

Addition: But then again, it also depends on whether the computer system has additional "intelligent" features. Sometimes software designers try to teach computer the nuances of mathematical expression and the way people usually write it which is against the strict syntactic rules, so it tries to "guess" what you really mean by breaking the strict rules.

You can try it out at WolframAlpha which uses the Mathematica software which is one of the most popular mathematical softwares used by professional mathematicians. When you type 1/2x, it actually guesses (http://www.wolframalpha.com/input/?i=1%2F2x) that you mean 1 over 2x. However, if you type 1/2xy, it goes back to the strict computer rule, and gives you (http://www.wolframalpha.com/input/?i=1%2F2xy) one divided by two, multiply by x, multiply by y.

Confusing. Which is why we should be as clear as possible when we input mathematical expression.

[surayahamdan]

Just a trivia, this math question was started on 4chan to troll people. There are some other variations but I'm just too lazy to find them.

[CissNei]

Just a trivia, this math question was started on 4chan to troll people. There are some other variations but I'm just too lazy to find them.

Won't be surprised. There's some troll potential in this one. That being said, I didn't get it off 4chan :P

Anyways as to the original question, I would've done gotten 288, and interpreted 1/2X as 1/2 * X.

Was curious about how people would interpret the "division" sign as opposed to the "/" sign.

[youngyew]

Best reply to the equation ever:
a-e8fzqv3CE
Do watch her other videos as well, she presents mathematics in such a fun way you would wish she was your maths teacher in high school!

It's like saying, "I would like some juice or water with ice".

WIN.

[Smilehoe]

ah, Vhart! She makes the most interesting maths videos. <3

[Cactus]

Best reply to the equation ever:
a-e8fzqv3CE
Do watch her other videos as well, she presents mathematics in such a fun way you would wish she was your maths teacher in high school!

It's like saying, "I would like some juice or water with ice".

WIN.

I almost cried when she drew crocodiles as a sign for some operation.:cry

And yes, I think the equation is dumb!

[Laavania]

I almost cried when she drew crocodiles as a sign for some operation.:cry

And yes, I think the equation is dumb!

me too :cry