Promil $1$ promil $\left(1‰\right)$ liczby $x$ to $0,001$ tej liczby, czyli $0,001x$.

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a)

$2‰$ liczby $300$ wynosi

$2‰\cdot 300=\frac{2}{10\cancel{0}\cancel{0}}\cdot 3\cancel{0}\cancel{0}=\frac{2}{10}\cdot 3=\frac{6}{10}=\underline{\underline{0,6}}$

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b)

$8‰$ liczby $1400$ wynosi

$8‰\cdot 1400=\frac{8}{10\cancel{0}\cancel{0}}\cdot 14\cancel{0}\cancel{0}=\frac{8}{10}\cdot 14=\frac{112}{10}=\underline{\underline{11,2}}$

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c)

$50‰$ liczby $100$ wynosi

$50‰\cdot 100=\frac{50}{10\cancel{0}\cancel{0}}\cdot 1\cancel{0}\cancel{0}=\frac{50}{10}\cdot 1=\underline{\underline{5}}$

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d)

$5‰$ liczby $1000$ wynosi

$5‰\cdot 1000=\frac{5}{1\cancel{0}\cancel{0}\cancel{0}}\cdot 1\cancel{0}\cancel{0}\cancel{0}=5\cdot 1=\underline{\underline{5}}$

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e)

$0,2‰$ liczby $1800$ wynosi

$0,2‰\cdot 1800=\frac{0,2}{10\cancel{0}\cancel{0}}\cdot 18\cancel{0}\cancel{0}=0,02\cdot 18=\underline{\underline{0,36}}$

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f)

$5,5‰$ liczby $180$ wynosi

$5,5‰\cdot 180=\frac{5,5}{100\cancel{0}}\cdot 18\cancel{0}=0,055\cdot 18=\underline{\underline{0,99}}$