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re: Bizarre Math Question and Answer breaks the internet - Sorry if already posted
Posted on 4/16/15 at 10:18 am to buckeye_vol
Posted on 4/16/15 at 10:18 am to buckeye_vol
quote:
You're making an additional assumption by solving the 2(9+3). Pretending things exist that don't is not the most "rational" solution. As explicitly stated that answer is 288. Therefore, fewer assumptions = more logical approach.
2(9+3) isn't explicit multiplication, it is multiplication by juxtaposition which is the exact same thing as 2X and no one would solve that as 2*X.
quote:
My problem with the answer 2 is to come to that answer either you have to make an assumption of implied parantheses--which is defensible--or you misapply the order of operations--which is not defensible.
There isn't implied parenthesis, the argument is that multiplication by juxtaposition always takes precedence.
This post was edited on 4/16/15 at 10:21 am
1
Posted on 4/16/15 at 12:10 pm to bgator85
quote:Here is the professor from Cal-Berkeley--who is arguing that both 2 and 288 are correct--has to say about Multiplication by Juxtaposition.
quote:
You're making an additional assumption by solving the 2(9+3). Pretending things exist that don't is not the most "rational" solution. As explicitly stated that answer is 288. Therefore, fewer assumptions = more logical approach.
2(9+3) isn't explicit multiplication, it is multiplication by juxtaposition which is the exact same thing as 2X and no one would solve that as 2*X.
There isn't implied parenthesis, the argument is that multiplication by juxtaposition always takes precedence.
quote:As he says, the non-algebraic representation makes one way or the other less clear. Furthermore, the best I can tell, there isn't clear consensus on whether it always takes precedence anyways.
Finally, the convention in algebra of denoting multiplication by juxtaposition (putting symbols side by side), without any multiplication symbol between them, has the effect that one sees something like ab as a single unit, so that it is natural to interpret ab+c or a+bc as a sum in which one of the summands is the product ab or bc. Without that typographic convention, the order-of-operations convention might never have evolved. When one has numbers rather than letters, one can't use juxtaposition, since it would give the appearance of a single decimal number, so one must insert a symbol such as ×, and there is less natural reason for interpreting 2 × 3 + 4 as (2 × 3) + 4 rather than 2 × (3 + 4), but I suppose that we do so by extension of the convention that arose in the algebraic context. Likewise, because addition and subtraction constitute one "family" of operations, and multiplication and division another, and perhaps also because the slant "/" doesn't seem to separate two expressions as much as a + or - does, we are ready to read a/b+c etc. as involving division before addition. But when it comes to a/bc, where the operations belong to the same family, the left-to-right order suggests doing the division first, while the "unseparated letters" notation suggests doing the multiplication first; so neither choice is obvious.
I say though that, given the syntax, it is best to limit assumptions, and solve as presented, which would result in 288.
This post was edited on 4/16/15 at 12:11 pm
Posted on 4/16/15 at 12:34 pm to lsupride87
People keep saying we are implying parenthesis to show there are two answers. I add no parenthesis and can easily say you added parenthesis. We are simply "ignoring" the left to right rule. Its not how we were taught to look the problem. Those saying left to right are assuming the person who wrote it did so with the intention of the solver to use that "rule"
But it's not a rule. It may be the way you always did it and it may be what teacher said. But it's just not really a real rule.
I mean look at the OP. Even Matt Damon solved it to be 2. And he's a genius janitor. So it must be a plausible solution.
But it's not a rule. It may be the way you always did it and it may be what teacher said. But it's just not really a real rule.
I mean look at the OP. Even Matt Damon solved it to be 2. And he's a genius janitor. So it must be a plausible solution.
Posted on 4/16/15 at 12:42 pm to KG6
It's a poorly written equation. The teacher who wrote it is either stupid or an a-hole.
Oh, and 288.
Oh, and 288.
Posted on 4/16/15 at 1:11 pm to KG6
quote:Math is a language. Languages have rules. Order of operations is a rule to guide the language. So you are incorrect sayings it's not a rule; it's more of a communication rule though.
But it's not a rule. It may be the way you always did it and it may be what teacher said. But it's just not really a real rule.
If you want to start a new mathematical language, you are free to, just like you can start your own written language.
This post was edited on 4/16/15 at 1:24 pm
Posted on 4/16/15 at 1:22 pm to SoDakHawk
Solve for x
48/x(9+3)=2
48/x(9+3)=288
48/x(9+3)=2
48/x(9+3)=288
Posted on 4/16/15 at 1:35 pm to KosmoCramer
The crappy division sign and moving the 2 by the parentheses tricked me at first. The answer is 288
Posted on 4/16/15 at 1:40 pm to Team Vote
quote:
48/2(9+3)
48 / ((2x9)+(2x3))
48 / (18+6)
48 / 24
=2
This is correct and anyone who thinks its 288 needs remedial math courses.
Posted on 4/16/15 at 1:42 pm to Eternally Undefeated
quote:
48/2(9+3)
48 / ((2x9)+(2x3))
48 / (18+6)
48 / 24
=2
quote:
This is correct and anyone who thinks its 288 needs remedial math courses.
Too bad you made assumptions and changed the original written equation once again, for those in denial, as written in any system, the answer is:
This post was edited on 4/16/15 at 1:47 pm
Posted on 4/16/15 at 1:42 pm to Eternally Undefeated
Good lord you butchered that
You worked the problem as if it were set up as
48/(2(9+3))
which is not the same as
48/2(9+3)
quote:
48/2(9+3)
48 / ((2x9)+(2x3))
48 / (18+6)
48 / 24
=2
You worked the problem as if it were set up as
48/(2(9+3))
which is not the same as
48/2(9+3)
This post was edited on 4/16/15 at 1:56 pm
Posted on 4/16/15 at 1:48 pm to Eternally Undefeated
48/2(9+3)=48x(1/2)x(9+3)
The order of operations is
PE(MD)(AS). Because division is a form of multiplication and subtracting is a form of addition. Therefore you would work from left two right with P then left to right with MD then left to right with AS.
288
The order of operations is
PE(MD)(AS). Because division is a form of multiplication and subtracting is a form of addition. Therefore you would work from left two right with P then left to right with MD then left to right with AS.
288
Posted on 4/16/15 at 1:50 pm to Pintail
15 pages... 15 fricking pages for just one several-year-old version of the same PEMDAS troll equations making their rounds on the internet.
Congrats to all of you mathematicians.
Congrats to all of you mathematicians.
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