• billwashere@lemmy.world
    link
    fedilink
    English
    arrow-up
    12
    arrow-down
    4
    ·
    edit-2
    1 day ago

    Multiplication is commutative dipshits.

    A x B = B x A

    So 1.1 x .9 is always going to be .99, regardless of the order. Didn’t we learn this in like middle school?

    (Edit … to be clear I’m calling the people in the image dipshits, not the people commenting here).

    • phlegmy@sh.itjust.works
      link
      fedilink
      arrow-up
      6
      arrow-down
      1
      ·
      24 hours ago

      Huh? We’re talking about percentages not multiplication. Where’d the 1.1 and .9 come from?

      • billwashere@lemmy.world
        link
        fedilink
        English
        arrow-up
        2
        arrow-down
        1
        ·
        edit-2
        18 hours ago

        If you increase something by 10% you’re doing this:

        (10% • X) + X

        (.1 • X) + X

        1.1 • X

        So you’re just multiplying the original value by 1.1. Similarly for subtracting 10% you’re multiplying by .9

        So the order in which you add or subtract 10% doesn’t matter. You always get the same number.

        • Ostrakon@lemmy.world
          link
          fedilink
          arrow-up
          7
          arrow-down
          1
          ·
          18 hours ago

          I have 100 dollars. I lose 10% of it. I now have 90 dollars. Now I increase my 90 dollars by 10%. Is it your assertion that 10% of 90 is 10?

          • billwashere@lemmy.world
            link
            fedilink
            English
            arrow-up
            2
            ·
            17 hours ago

            No. Because increasing 90 by 10% is:

            90 • 1.1 = 99

            Percentage is relative to current value, not previous calculations. 10% of 90 is 9.