Have you seen this on the web? Can you solve it? 8÷2(2+2)=?

1.

Yeah, its a trick question it depends on what system of hierarchy of the operations that you use. The answer is either 1 or 16 (PEMDAS or BODMAS respectively).

8÷2(2+2)=?

4 x 4 = 16

The problem is written incorrectly and is ambiguous. Both 1 and 16 can be correct.

Correct, the use of the division symbol (÷) is discouraged for this reason.

8 / 2 * (2 + 2)
Parentheses first so resolves to
8 / 2 * 4
Preliminary work done, now start over
Division and multiplication are of equal precedence so evaluate left to right
8 / 2 = 4
4 * 4 = 16

How's it ambiguous?

PEDMAS

Means you do parentheses first (P)
Exponents next (E)
....

BUT what they don’t always say is you do all your Multiplication and Division at the same time “LEFT TO RIGHT”....

Which means it’s = 8/2(2+2)

Converts to 8/2*4... which is done strictly left to right...

OR. 4*4 =16

So there is only one correct answer.

PEDMAS - if only it was that simple. In C programming language:



So I use parentheses freely, helps keep you sane.

Oh I see, the expression isn't ambiguous, people don't understand the mnemonics.

Here's the foxnews article the question came from: MATH PROBLEM

You folks are much smarter than I, well, yes just that.

Answer is 16, because I remember that you need to Please Excuse My Dear Aunt Sally.

It’s a common mistake to keep working from where the paran’s where but that means working “right to left” vs. left to right... (and that is arse backwards).. and results in a wrong answer.

Fugg 16, the answer is 1!

I only see 16, don’t know how you get to 1.

Here's one of the comments from the article:

8÷2X(2+2) = 16
8÷2(2+2) = 1
Final answer.
People who are poor in math will add that multiplication sign in their delusional minds and then follow PODMAS to come up with 16
People who are proficient in math will not add that multiplication sign and still follow PODMAS exactly and come up with 1.

To get 1, you have to add a set of parentheses: 8÷(2(2+2)) = 1

Didn't study for a pop quiz this morning. I thought the always correct answer was 6.5

Maybe today, but in a year or two , the correct answer may be 6

Or 7.

I'm surprised you folks didn't learn to Please Excuse My Dear Aunt Sally in middle school. Apply that, and it's easy. It's 16. Did it in my head in seconds, and I'm no math wiz. What's supposed to be hard about this problem? Why are people getting 1 as the answer?

You guys are all wrong - the right answer is Creedmoor

Bwahahahaha

Using 1 grain of powder or 16?

PEMDAS doesn't mean you do multiplication before division. They're at the same order of operation, meaning you do them in order, left to right.

No, PEMDAS and BODMAS mean the same thing, just different terminology 'round the world.

It really means P,E,MD,AS.

Nope.

It's Please End My Depression and Suffering.

Yep. Is that why folks are wrongly getting 1?

If you solve it the way it is written the answer is two. You cannot just arbitrarily add or remove parentheses and such. You have to solve the problem, not CHANGE the problem.

KIDDING! Trying to throw out a dumb answer like all the others. The real answer is ZERO

People like me who are stuck on RPN come up with 1 too.

As a programmer I agree, 16 is the only correct answer

I came up with 16 working left to right

Thank you!

As you're supposed to.

Where's Mathman?

This History Professor came up with 1.

I had a calculus teacher in college tell me once that sometimes there are no right answers. Wtf??


I carried her in a Hefty garbage bag full of fresh blue lake green beans after that, got an A in that class. 👍

Well, I'm not Mathman and I'm not a programmer, but I do have an engineering degree, and did get a math minor, and I came up with 1. Eight in the numerator over 2 times 4 in the denominator is how I took it. It is ambiguous.

Edited to add, I'm also almost 60 years old and school was a long time ago.

wouldn't rpn come out to 2,2+8,2,/,* which is 16 (Been awhile since I dealt with RPN!)

The only ambiguity is the lack of a * time, it's implied, or is an exponent?

2 ent 2+ 2* 2/ right to left = 1. I reserve the right to be wrong but that's the way I worked it.

I am with Pugs. Been running HP calcs since 1974.

Man, you guys are speaking another language right now.

2(...) The 2 adjacent to the parentheses means 2 times (...). Explicitly written it's 2*(...)

The (2+2) "parentheses object" is 4.

So written out it's 8 / 2 * 4.

These operations are on the same footing, so are evaluated in order, left to right. 8/2 = 4, so now we have 4 * 4 = 16.

An earlier poster declaring "2 times 4" to be in the denominator effectively inserts parentheses that weren't there, as in 8/(2*4), or 8/(2(2+2)).

................

Thank you!!

=1+15

or you could follow these rules :

https://en.wikipedia.org/wiki/Reverse_Polish_notation

Didn't you just insert an asterisk that wasn't there?

Partly, the answer depends on whether you are doing programming or doing math.

The divisor bar also carries implicit parentheses. The expression could properly and unambiguously be written

8÷[2(2+2)] so that 2(2+2) all appears under the divisor bar. Lacking easy graphics, I've used [] to indicate the implicit parentheses of the divisor bar.

In programming, the expression could be interpreted as

8/2*4.

The asterisk indicates a multiplication that's already there, just to make it stick out like a sore thumb. It does not change the meaning or grouping of terms.

The extra inserted parentheses do change meaning/grouping.

My friend Charlie, and I agree with him many times says...............









Stihl.


Geno

PS, when I was taught, by Catholic nuns (Sisters of St Joseph of Orange order), the answer most likely would have been 1.

PPS of course, we had a few lay teachers there too, so it may have been 16

He was just trying to clarify what 2( means.

Clyde

WWSS?


(What would Spock say ?)

Geno

PS I sure wish they had posed this question on the Big Bang Theory before the final episode. Sheldon would have settled it.

But what is the answer in Baltimore?

Upon further review, and consultation with others I have come to the conclusion the answer is



Settled!

Geno

Forgot about that.

It is interesting now days, when you tell someone to do the math, they look at you like your some kind of alien. I do this routinely including at my work where we have to do some math occasionally. The youngsters look at me like I am nuts or asking them to do something they should not have to do. I jokingly asked a young engineer once to calculate how many ping pong balls it would take to lift the Titanic off the bottom of the ocean and get it to the surface, by god she liked math and went home and came back the next morning with the answer. She showed me her math (way over my head) so I don't know if she was correct or not, but I give her credit.

I still have never figured out.............................


How much wood

could a woodchuck chuck

if a woodchuck could

chuck wood?


Geno

PS 42? cords? logs? sticks?

If a chicken and a half can lay an egg and a half in a day and a half, how long does it take a centipede with a wooden leg to kick all of the seeds out of a dill pickle?

LOL.

If you're paddling down the river.....................................





how many pancakes does it take to cover a doghouse?

Geno

Perfectly structured Aristotelian syllogism ... NOT LOL.

Fascinating.

Aristotle was a bore.

Geno

Whatever the answer to the OP question.............




Scotty would still tell Kirk he can't make any more power.


Geno

Dialithium crystals ain't what they used to be....

I have to take my pants down to count to 21, so I'm not the guy to help in this.

Or to go to the casino to play blackjack with either...

Scotty knew how to play the game.

Yep. Exactly.

They're doing all the multiplication, before the division. Not at the same time, left to right.

We just learned the precedents, no mnemonics. Guess it was a good thing. Of equal precedents arithmetic operators associate left to right.

leben de leben

IMO, 2(2+2) is the value that must be determined first. I think that would be easier to see if the problem was written as

8 / 2(2+2)

2(2+2) looks an awful lot like a denominator to me. Can't move that first 2 to the numerator because you must multiply and divide first.

The answer is 1

Rocket science eh...

No kidding.

A quick anecdote: Though retired I was asked to sit in on a meeting on a petro project with US, Norwegian, UK and Canadian involvement where as an icebreaker the guy in charge had the room of dozens of engineers of all disciplines, marine surveyors, geologists and the like take a piece of scrap paper and do this because he'd seen it on the internet. All but one derived the correct "16", and the one who didn't was a business development lady who was sitting in...she got "2"?? Seemed like the room was split as to whether this increased confidence in the diverse team and their educations from around the globe, with those who were somewhat amazed or insulted that the PM had brought it up in the first place.

That's an example of why I like the liberal use of parenthesis and operators. They leave no doubt.

For 16 I would have written it as (8/2)*(2+2) or even (8/2)(2+2) is better.

Interesting. I use a 41CV with "Applications" and Math/Stats ROM pacs. I get 16

The calculation takes the parenthetic first (2+2) and stores the resulting 4: STO 01 (or in ALPHA STO A)

It then solves left-to-right:

8 ENTER 2 ÷ RCL 01 X

16

I consider it a poorly written problem. If I saw it in code, I would question whether or not the original programmer knew what the result should be.

2(2+2) and 2*(2+2) are synonymous. The * is implied whether it's written or not. The only way the expression can be used as a denominator is to write it as (2(2+2)). Otherwise it's solved 8 / 2 * (2+2)

Hm? What's wrong with a / b * (c + d) ? Of course in the real world if it was just constants you or the preprocessor would evaluate it. As 16.