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Why do we use division when we use per something?

  1. Oct 10, 2015 #1
    Why do we use division/fractions to represent per something?
     
  2. jcsd
  3. Oct 10, 2015 #2

    phinds

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    Three per hundred, for example, means 3 out of 100, so we can write it as a ratio, 3:100, or a fraction, 3/100
     
  4. Oct 10, 2015 #3

    pasmith

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    3 per hundred is 3:97.
     
  5. Oct 10, 2015 #4

    phinds

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    Ah yes, good catch. I should have said "three out of a hundred, or 3/100"
     
  6. Oct 10, 2015 #5
    Doesn't really answer my question. I am asking why that is.
     
  7. Oct 10, 2015 #6

    Mark44

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    Why it is, is because of what the words mean. When we say, for example, 6 per cent (literally 6 per 100) we are expressing a ratio: ##\frac 6 {100}##. It's similar for units such as mph (miles per hour). We are talking about a ratio of miles driven per (divided by) the time in hours.
     
  8. Oct 10, 2015 #7

    symbolipoint

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    "per" distinctly indicates both DIVISION and FRACTION.
     
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