Percentage

Percent (%) means hundredth or "of hundred". The following applies:

$p\%=\frac{p}{100}$

Examples

$1\%=\frac1{100}=0.01$
$100\%=\frac{100}{100}=1$
$25\%=\frac{25}{100}=0.25$

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Hint

Percentage information is used to

indicate proportions of a whole.
(e. g.: "40% of the respondents are female")
indicate increases and decreases.
(e. g.: "the revenue increased by 20 percent")

Per mille

Per mille (‰) means thousandth or “of thousand”. The following applies:

$p‰=\frac{p}{1000}$

Examples

$1‰=\frac1{1000}=0.001$
$250‰=\frac{250}{1000}=0.25$
$1000‰=\frac{1000}{1000}=1$

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Hint

In order to convert per mille to percentage, divide by 10.

Example: $10‰=\frac{10\color{red}{:10}}{1000\color{red}{:10}}=\frac{1}{100}=1\%$