48÷2(9+3)=?

[Casper]

There isn't really. Both answers could be, because it's one of those problems with a loophole. If you search it on google websites you'll find that it is used for trolling and to start confrontations. It was a fun time, but it's worn out already in just 2 days.

No loophole. As written, it's 288. It's the point of the problem, to trick you. Follow the order of operations, and you get your answer of 288. Fuck up, and you get 2.

[obesityrules]

There isn't really. Both answers could be, because it's one of those problems with a loophole. If you search it on google websites you'll find that it is used for trolling and to start confrontations. It was a fun time, but it's worn out already in just 2 days.

^this

looks like casper has become the biggest troll on OR

[OsuMj]

OK, from someone who is one with computers, the answer would seem to be 288 because that's the way computers calculate. From someone who is more on the math side of things, the lack of * next to parenthesis always notes that it belongs to the parenthsied term.... since its a math equation and not a computer problem, that's why its 2.

again, its ok that you suck at life if you get 288.... we're still friends. I will just think less of your intelligence.

[Casper]

OK, from someone who is one with computers, the answer would seem to be 288 because that's the way computers calculate. From someone who is more on the math side of things, the lack of * next to parenthesis always notes that it belongs to the parenthsied term.... since its a math equation and not a computer problem, that's why its 2.

again, its ok that you suck at life if you get 288.... we're still friends. I will just think less of your intelligence.

That's just sad. I thought you were smart?

[SWing'R]

When you punch the equation into a Google search is says 288

I like this answer I found on another forum...

"There's no good answer to a bad question. The equation is incorrect to begin with. If you're going to use the ÷ symbol, you need to place parentheses where needed. There is no correct answer to this problem."

Edited April 13, 2011 by SWing'R

[chevysoldier]

2+2≠4

[CoolWhip]

It is the osu education

[Cypress]

the 2(9+3) without the * implies it belongs to the parenthesied term. deal with it. the answer is 2.

This was my original thought. Damn it to hell! Can we get an expert in on this? Wait...we've already done that...a few times.

[ReconRat]

I'm curious... I posted a proof that pins down the correct answer.

But I didn't say which one was the answer.

And nobody asked which one it was?

You'all weird.. Although all you have to do is enter the proof equations in a calculator and look for yourself.

[Cypress]

That was far too much for me to read. My ADD kicked in during your first sentence.

[ReconRat]

That was far too much for me to read. My ADD kicked in during your first sentence.

It took me what... 31 hours to get to a place where I could concentrate long enough to both figure it out and write it. Don't feel bad.

[CoolWhip]

Use the calculator for proof of it's own results:

A reverse proof to solve for unknown will demonstrate this.

48÷y(9+3)=2 or 48÷y(9+3)=288

Substituting y for the implicit multiplicand, y will equal 2 for whichever answer is correct, the 2 or the 288

Neither of these give the correct answer, both are false.

The calculator can't prove it. Or the calculator proves the calculator can't do it.

http://www.wolframalpha.com/input/?i=48%C3%B7y%289%2B3%29%3D288

or it proves you need a better calculator. This gets the correct answer... for drum roll please...... 288!!!!!!!!!!!!!!!

[buildit]

I'm curious... I posted a proof that pins down the correct answer.

But I didn't say which one was the answer.

And nobody asked which one it was?

You'all weird.. Although all you have to do is enter the proof equations in a calculator and look for yourself.

After consulting my step father who is good enough at math to have tutored me through diff-Q, I feel very comfortable with the answer being 288. I denounce all other answer as heracy.

[RSparky]

I feel it depends on how you write it. Having read the first and last pages only, here is my response: 2.

In my engineering math, x(y+z) is usually done first, as the /(can't find the actual sign) can be assumed to separate the statement.

As far as trusting calculators and wolframalpha for algebra, goes... I don't. There have been many a time that my improperly written equations, whether straight from the book, or derived, have gotten the wrong answer. Wolframalpha is programmed to make assumptions when it doesn't have a perfectly prescribed set of rules.

[ReconRat]

http://www.wolframalpha.com/input/?i=48%C3%B7y%289%2B3%29%3D288

or it proves you need a better calculator. This gets the correct answer... for drum roll please...... 288!!!!!!!!!!!!!!!

You don't get it. This isn't about the calculation in question.

It's about the ability of the calculator to do a proof of that calculation.

It did indeed give an answer for both. Both of the original equations for result 2 and 288 were wrong.

After a change for implied distribution, one result was true, and one was false.

So for the four equations, there were three wrong answers and one right.

Again, this is a proof. The answers should be all be wrong, with one correct answer. The correct answer, is proof of the one original equation with answer.

The purpose of a proof, is to find which one was the correct answer.

I have done that. I know which one is correct.

Run the proof equations yourself, and see what you get.

edit: if I did what you show at wolframalpha, I would get multiple correct answers. That is not appropriate for a proof.

Edit: just tried it. There are two results at wolframalpha for correct. And they cross over. That pretty much invalidates the wolframalpha ability to handle calculation of a proof.

Edited April 14, 2011 by ReconRat

[Bad324]

my stepdad who is too, ridiculously smart and has an engineering degree as well as business degree and MBA says 288 as well so thats what I'm going with

[NinjaNick]

Well we can gather one type of conclusion from this thread...

Don't give engineers any credit for being good at simple math. Plus the answer is more in the terms of.........INCONCLUSIVE!

[ReconRat]

Well we can gather one type of conclusion from this thread...

Don't give engineers any credit for being good at simple math. Plus the answer is more in the terms of.........INCONCLUSIVE!

What I see is the danger of trusting calculations from a calculator.

It appears to be worse than I ever thought. There is considerable variety.

This presents a clear danger to people both now and in the future.

Anything calculated wrong in transportation vehicle design will potentially involve people dying.

[NinjaNick]

Calculators shouldn't be used hardly at all.

[tyler524]

What I see is the danger of trusting calculations from a calculator.

It appears to be worse than I ever thought. There is considerable variety.

This presents a clear danger to people both now and in the future.

Anything calculated wrong in transportation vehicle design will potentially involve people dying.

Good thing I just design the giant washing machines and rely on our controls guys to program the robots correctly so it is up to them to make sure that the parts go where they need to.

[dorifto240]

Remember when your math teacher said numbers never lie, 2+2 always equals four:

They were wrong.

[CoolWhip]

You don't get it. This isn't about the calculation in question.

It's about the ability of the calculator to do a proof of that calculation.

It did indeed give an answer for both. Both of the original equations for result 2 and 288 were wrong.

After a change for implied distribution, one result was true, and one was false.

So for the four equations, there were three wrong answers and one right.

Again, this is a proof. The answers should be all be wrong, with one correct answer. The correct answer, is proof of the one original equation with answer.

The purpose of a proof, is to find which one was the correct answer.

I have done that. I know which one is correct.

Run the proof equations yourself, and see what you get.

edit: if I did what you show at wolframalpha, I would get multiple correct answers. That is not appropriate for a proof.

Edit: just tried it. There are two results at wolframalpha for correct. And they cross over. That pretty much invalidates the wolframalpha ability to handle calculation of a proof.

yea... I definitely solved this in my head and got 288. I just included the calculator links to help people see why it is right. It is 288. BTW you are using Wolfram Alpha wrong because it gives the correct answer for the proof you provided. I'm sorry if this new fangled technology is too tough for ya

[fusion]

yea... I definitely solved this in my head and got 288. I just included the calculator links to help people see why it is right. It is 288. BTW you are using Wolfram Alpha wrong because it gives the correct answer for the proof you provided. I'm sorry if this new fangled technology is too tough for ya

Wolfram Alpha makes an incorrect assumption about a ambiguous problem and ends up providing the wrong answer.

[Casper]

Calculators shouldn't be used hardly at all.

Sadly enough, kids these days don't know how to do basic math without one. It amazes me the number of kids who can't do basic multiplication in their heads. I was always the kid getting in trouble for not showing work on tests and homework. My dad taught me how to do it in my head starting before I began school. I can't tell you how many times a teacher gave me an F on a paper saying I had to have cheated because there was no way to do the work in your head. I'd of course argue. They'd give me a random problem, and I'd answer it in a minute or two. I remember my AP geometry teacher my freshman year of high school arguing with me over how I solved proofs. She'd never seen the answer before, but when she went through it backwards, she verified my answer was also correct. I definitely rely on calculators more now, but watching kids struggle while using calculators is just depressing. Technology makes people dumber. Ironic that I'm a computer guy. LOL

[JonS]

Technology makes people dumber. Ironic that I'm a computer guy. LOL

http://www.youtube.com/watch?v=CD2LRROpph0