Timnotep

April 9th, 2011 at 12:44 AM ^

"You can't compare the nuances of human language to the hard and fast rules of mathematics. They're not even in the same ballpark."

I find at least in this case that they're very comparable. The very fact that people can't agree on the way in which this problem is done tells me that google isn't necessarily the best source.

NOLA Wolverine

April 9th, 2011 at 12:53 AM ^

I don't get why you quoted my post, as you didn't address the comparision. The fact that people can be wrong doesn't suggest anything other than that we are still human.

---

I'd say the fact that the refactored version of the calculator supports 288 is telling. That's an issue of how a programmer decides to handle methods, and they apparently chose to differentiate between multiplication and the distributive property the first time around. 

Timnotep

April 9th, 2011 at 1:00 AM ^

I see exactly where the division is made, you're either using the distributive property and coming out with 2 (like I am) or you're not and coming out with 288 (like you are). And clearly it's a point of contention between people who are much better at math than I am (as Ti keeps waffling, and my parents are using the distributive property, whereas others aren't).

But when it all comes down to it I'm not heading into a career field that will demand the answer to this problem. At this point I'm spending way too much energy arguing something I'm not all that interested in. So I'm just not going to argue it any further.

Shaqsquatch

April 9th, 2011 at 12:38 AM ^

Dude, you are completely wrong, just drop it, you're sounding like one of the RCMB posters by attempting to reason this argument. You can't just arbitrarily add parentheses where they don't exist. 2(9+3) is EXACTLY the same as 2*(9+3). The only operation affected by the parentheses is the addition. Just because something is next to a set of parentheses doesn't mean it gets priority all of the sudden, it's just a shorthand way of writing multiplication.

Shaqsquatch

April 9th, 2011 at 12:50 AM ^

You haven't called other people an idiot because they are RIGHT. The answer is 288, there is no question, no ambiguity, no room for reason. It is a simple mathematical equation, and the answer is 288. One of your calculators obviously has something wrong with it from that screencap, because it is simply giving you the wrong answer to the question. A TI-85 is a very old model, correct? The code is likely out of date and that's why they keep making new models.

Shaqsquatch

April 9th, 2011 at 12:59 AM ^

The TI-83 isn't older than the TI-85... They don't go in numerical order. The TI-85 is over 20 years old, the 83 and 86 are newer models which have since corrected for the error.

I'm basing my argument off of personal experience and qualification here, not a calculator, which are, as you have seen, prone to human error.

dmblue

April 9th, 2011 at 1:12 AM ^

lol...you keep beating me to it.

 

Ti-85 is a very old calculator.  In fact, the only older TI graphing calculator is the TI81.  73, 80 83, 84, 86, 89 and 92 all came out after the 85.

 

I am pretty sure this error is fixed in the later calculators.

Ernis

April 9th, 2011 at 12:31 AM ^

2(9+3) = 2*(9+3)

48/x = 48*(1/x)

If a multiplication sign binds an adjacent term to the parentheses, then... according to your logic...

48/2*(9+3) =

48/((2*9)+(2*3)) =

48*(1/((2*9)+(2*3))) =

48*((1/(2*9))+(1/(2*3))) =

(48*(1/(2*9))) + (48*(1/(2*3))) =

2.66667 + 8 =

10.6666667

Which, no, obviously

Timnotep

April 9th, 2011 at 12:09 AM ^

because the 2 is being multiplied by the 9+3 in the parentheses, therefore you have reduce that part first.

Then you can take the result of that and divide 48 by it. Because the 48 has no relationshipr with the (9+3) it gets done last.

UMxWolverines

April 9th, 2011 at 12:39 AM ^

for the last time, the 2 does not go with the parentheses BECAUSE the 48 is in front of it! When you have simply 2(9+3) which equals 24 the 2 gets distributed. But that isn't the case. The only way the 2 can go with the (9+3) is if you put it in another set of parentheses. 

48/2(9+3) is what the problem is

48/(2(9+3)) is what would get you 2, but that isn't the same problem that's being asked.

Ernis

April 8th, 2011 at 11:49 PM ^

The distributive property is a statement of equivalence. It is not a procedure. If you factor out to 2*9 and 2*3 and get a different answer than you would if you didn't factor the terms out, it's a sign that YOU'RE DOING IT WRONG

48/2*(9+3) =

48/2/12 =

288

!!! does not equal !!!

48/((2*9)+(2*3)) =

48/24 =

2

Therefore the distributive property has been incorrectly applied.

RickH

April 8th, 2011 at 11:27 PM ^

LOL, this problem has gotten everywhere.  It was posted in Misc on bodybuilding.com (I posted in it) and got over 3000 poll votes (between 2 and 288) and an 80 page thread.

The answer is 288 damnit!  We're still fighting about it over there...

Noleverine

April 8th, 2011 at 11:32 PM ^

Haha this made my night.  By far one of the best discussions on their blog I've read in a while.

If it were written in terms of goats and cows, I think they might get it...

 

WolvinLA2

April 8th, 2011 at 11:56 PM ^

I don't know guys, I've done it like 20 times and I've gotten 65 every time.  Then again, I was a sociology major.

Or maybe it's because I'M BANGING LIKE 10 ASIANS AND LATINAS AND YOUR MOM AND SISTER AND STEP-DAD ALL WITH 3 TI-11,000,000S IN MY HAND RIPPING THROUGH SOME MATH YOU DUMB MICHIGAN GRADS/STUDENTS!!!!1!!1!

wmu313

April 8th, 2011 at 11:56 PM ^

This simple math problem has spread through the interwebz like a bad case of herpes. I'm pretty sure if everyone finally comes to a consensus on the correct answer, something is going to happen. This must be the final boss of the internet.

smwilliams

April 9th, 2011 at 12:10 AM ^

I understand arguments about movies, music, sports, etc. because none of these things are absolute. But math. I mean, the internet will find a reason for a 20-page message board about anything.

And...

As somebody on RCMB correctly pointed out, applying algebraic functions to an arithmetic problem isn't correct.

48/2(9+3)

doesn't mean you distribute the 2.  If it was written as 48/[2(9+3)], then yes, 2 would be correct.

It's not so the correct solution is...

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

48/2(12) = 24(12)

24(12) = 288

 

 

JRuiz

April 9th, 2011 at 1:53 AM ^

It might cause less confusion if you write it this way:

 

48 / 2(9+3)=

48 / 2(12)=

48 / 2 * 12 =

24 * 12 =

288

When you remove the parentheses it makes it  much eaisier to read IMO

 

 

BlockM

April 9th, 2011 at 12:31 AM ^

My favorite part is that the people who are arguing that it's actually 2 know deep down in their heart that it's 288, but they just don't want to admit to themselves they got it wrong at first. I know because I was there for about 10 minutes.

I will say this though: 99.9% of the time someone writes 2(9+3) within some larger equation, they mean (2(9+3)) regardless of context. The question isn't technically ambiguous, but it's designed to go against how anyone that has graduated from middle school would write it out. Besides this question and probably a couple when we were learning about order of operations in 3rd grade, I've never seen an equation written out this way instead of (48/2)(9+3)

Farnn

April 9th, 2011 at 12:35 AM ^

I just want to ask how people can be sure that the 48 isn't sitting on top of a wide bar that is resting on top of the 2(9+3) part. You wouldn't include a second set of parenthesis if you just had 2(9+3) as the denominator.

MaizeAndBlueWahoo

April 9th, 2011 at 12:41 AM ^

By the way, I think it's 2, not 288.

If you saw 1/2x, you shouldn't equate that to .5x (that is, 1 divided by 2 then times x), you should read 1 divided by (2x).  I think the fact that my calculator gives two different answers depending on whether you put a multiplication sign in between 2 and (9+3) is proof enough for me.