• billwashere@lemmy.world
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      4 days 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
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        4 days 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
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          4 days 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.