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 :)

  • Flax@feddit.uk
    link
    fedilink
    English
    arrow-up
    0
    ·
    11 months ago

    Division comes before Multiplication, doesn’t it? I know BODMAS.

    • Spacehooks@reddthat.com
      link
      fedilink
      English
      arrow-up
      0
      ·
      11 months ago

      This actually explains alot. Murica is Pemdas but Canadian used Bodmas so multiply is first in America.

      • ggppjj@lemmy.world
        link
        fedilink
        arrow-up
        0
        ·
        11 months ago

        As far as I understand it, they’re given equal weight in the order of operations, it’s just whichever you hit first left to right.

        • Spacehooks@reddthat.com
          link
          fedilink
          English
          arrow-up
          0
          ·
          11 months ago

          Yeah 100% was not taught that. Follow the pemdas or fail the test. Division is after Multiply in pemdas.

          I put the equation into excel and get 9 which only makes sense in bodmas.

            • Spacehooks@reddthat.com
              link
              fedilink
              English
              arrow-up
              1
              arrow-down
              1
              ·
              8 months ago

              The y(n+1) is same as yn + y if you removed the “6÷” part. It’s implied multiplication.

                • Spacehooks@reddthat.com
                  link
                  fedilink
                  English
                  arrow-up
                  1
                  ·
                  8 months ago

                  Well I’m not seeing the difference here. Yn+y= yn+y = y(n+1) = y × (n +1) I think we agree with that.

                  • 💡𝚂𝗆𝖺𝗋𝗍𝗆𝖺𝗇 𝙰𝗉𝗉𝗌📱@programming.dev
                    link
                    fedilink
                    English
                    arrow-up
                    1
                    arrow-down
                    2
                    ·
                    edit-2
                    8 months ago

                    Ok, that’s a start. In your simple example they are all equal, but they aren’t all the same.

                    yn+y - 2 terms

                    y(n+1) - 1 term

                    y×(n +1) - 2 terms

                    To see the difference, now precede it with a division, like in the original question…

                    1÷yn+y=(1/yn)+y

                    1÷y(n+1)=1/(yn+y)

                    1÷y×(n +1)=(n +1)/y

                    Note that in the last one, compared to the second one, the (n+1) is now in the numerator instead of in the denominator. Welcome to why having the (2+2) in the numerator gives the wrong answer.