https://zeta.one/viral-math/

I wrote a (very long) blog post about those viral math problems and am looking for feedback, especially from people who are not convinced that the problem is ambiguous.

It’s about a 30min read so thank you in advance if you really take the time to read it, but I think it’s worth it if you joined such discussions in the past, but I’m probably biased because I wrote it :)

• @[email protected]
884 months ago

If you are so sure that you are right and already “know it all”, why bother and even read this? There is no comment section to argue.

I beg to differ. You utter fool! You created a comment section yourself on lemmy and you are clearly wrong about everything!

You take the mean of 1 and 9 which is 4.5!

/j

• @wischiOP
384 months ago

🤣 I wasn’t even sure if I should post it on lemmy. I mainly wrote it so I can post it under other peoples posts that actually are intended to artificially create drama to hopefully show enough people what the actual problems are with those puzzles.

But I probably am a fool and this is not going anywhere because most people won’t read a 30min article about those math problems :-)

• @[email protected]
16
edit-2
4 months ago

Actually the correct answer is clearly 0.2609 if you follow the order of operations correctly:

6/2(1+2)
= 6/23
= 0.26

• @[email protected]
13
edit-2
4 months ago

Nah man, distribute the 2.
6/2(1+2)
= 6/2+4
= 3+4
= 7

This is like 4st grayed maff.

• @wischiOP
54 months ago

🤣 I’m not sure if you read the post but I also wrote about that (the paragraph right before “What about the real world?”)

• @[email protected]
7
edit-2
4 months ago

I did read the post (well done btw), but I guess I must have missed that. And here I thought I was a comedic genius

• @wischiOP
54 months ago

@Prunebutt meant 4.5! and not 4.5. Because it’s not an integer we have to use the gamma function, the extension of the factorial function to get the actual mean between 1 and 9 => 4.5! = 52.3428 which looks about right 🤣

• @[email protected]
14 months ago

Not sure if sarcastic and woosh, or adding to the joke ಠ_ಠ

• Redjard
84 months ago

The mean of 1 and 9 is 5

• pitninja
44 months ago

I think you got hit hard by Poe’s Law here. Except it’s more like people couldn’t tell if you were jokingly or genuinely getting your math wrong… Even after you explained you were joking lol

• Redjard
14 months ago

If one doesn’t realize you’re op, the entire thing can be interpreted very differently.
Then “Not sure if sarcastic and woosh, or adding to the joke ಠ_ಠ” could be interpreted as something like “I’m not sure if you are adding to the joke and I’m not understanding it”.

• Th4tGuyII
60
edit-2
4 months ago

The answer realistically is determined by where you place implicit multiplication (or “multiplication by juxtaposition”) in the order of operations.

Some place it above explicit multiplication and division, meaning it gets done before the division giving you an answer of 1

But if you place it as equal to it’s explicit counterparts, then you’d sweep left to right giving you an answer of 9

Since those are both valid interpretations of the order of operations dependent on what field you’re in, you’re always going to end up with disagreements on questions like these…

But in reality nobody would write an equation like this, and even if they did, there would usually be some kind of context (I.e. units) to guide you as to what the answer should be.

Edit: Just skimmed that article, and it looks like I did remember the last explanation I heard about these correctly. Yay me!

• @wischiOP
274 months ago

Exactly. With the blog post I try to reach people who already heared that some people say it’s ambiguous but either down understand how, or don’t believe it. I’m not sure if that will work out because people who “already know the only correct answer” probably won’t read a 30min blog post.

• Th4tGuyII
144 months ago

Unfortunately these types of viral problems are designed the attract people who think they “know it all”, so convincing them that their chosen answer isn’t as right as they think it is will always be an uphill challenge

• sverit
24 months ago

Yeah, that’s why fractions are good thing.

• @[email protected]
24 months ago

yeah, our math profs taught if the 2( is to be separated from that bracket for the implied multiplication then you do that math first, because the 2(1+2) is the same as (1+2)+(1+2) and not related to the first 6.

• Th4tGuyII
2
edit-2
4 months ago

So you were taught strong juxtaposition then, where the implicit multiplication takes priority?

• @[email protected]
24 months ago

if it was 6÷2x(2+1) they suggested do division and mult from left to right, but 6÷2(2+1) implied a relationship between the number outside the parenthesis and inside them, and as soon as you broke those () you had to do the multiplication immediately that is connected to them. Like some models of calculatora do. wasn’t till a few yeara ago that I heard people were doing it differently.

• if it was 6÷2x(2+1) they suggested do division and mult from left to right, but 6÷2(2+1)

Correct! Terms are separated by operators and joined by grouping symbols, so 6÷2x(2+1) is 3 terms - 6, 2, and (2+1) - whereas 6÷2(2+1) is 2 terms - 6 and 2(2+1), and the latter term has a precedence of “brackets”, NOT “multiplication”. Multiplication refers literally to multiplication signs, which are only present in your first example (hence evaluated with a different order than your second example).

Also noted that the OP has ignored your comment, seeing as how you pointed out the unambiguous way to do it.

• implicit multiplication

Some place it above explicit multiplication and division,

Which is correct, seeing as how we’re solving brackets, and brackets always come first.

But if you place it as equal to it’s explicit counterparts, then you’d sweep left to right giving you an answer of 9

Which is wrong.

Since those are both valid interpretations of the order of operations

No, they’re not. Treating brackets as, you know, brackets, is the only valid interpretation. “Multiplication” refers literally to multiplication signs, of which there are none in this problem.

But in reality nobody would write an equation like this

Yes they would. a(b+c) is the standard way to write a factorised term.

• @[email protected]
58
edit-2
4 months ago