$a)$

$\frac{9}{72} = \frac{1}{8}$

$\frac{1}{8} \cdot 100 % = 12 \frac{1}{2} %$

$\frac{4}{72} = \frac{1}{18}$

$\frac{1}{18} \cdot 100 % = 5 \frac{5}{9} %$

$\frac{18}{72} = \frac{1}{4}$

$\frac{1}{4} \cdot 100 % = 25 %$

$\frac{27}{72} = \frac{3}{8}$

$\frac{3}{8} \cdot 100 % = 37 \frac{1}{2} %$

$\frac{72}{72} = 1$

$1 \cdot 100 % = 100 %$

$\frac{108}{72} = \frac{3}{2}$

$\frac{3}{2} \cdot 100 % = 150 %$

$\frac{144}{72} = 2$

$2 \cdot 100 % = 200 %$

$b)$

$1 m = 100 c m$

$\frac{1}{100} \cdot 100 % = 1 %$

$\frac{15}{100} = \frac{3}{20}$

$\frac{3}{20} \cdot 100 % = 15 %$

$\frac{90}{100} = \frac{9}{10}$

$\frac{9}{10} \cdot 100 % = 90 %$

$\frac{25}{100} = \frac{1}{4}$

$\frac{1}{4} \cdot 100 % = 25 %$

$\frac{50}{100} = \frac{1}{2}$

$\frac{1}{2} \cdot 100 % = 50 %$

1m=1000mm

$\frac{1}{1000} \cdot 100 % = 0, 1 %$

$c)$

$1 k m = 1000 m$

$\frac{1}{1000} \cdot 100 % = 0, 1 %$

$\frac{350}{1000} = \frac{35}{100}$

$\frac{35}{100} \cdot 100 % = 35 %$

$\frac{1000}{1000} = 1$

$1 \cdot 100 % = 100$

$\frac{840}{1000} = \frac{84}{100}$

$\frac{84}{100} \cdot 100 % = 84 %$

$\frac{100}{1000} = \frac{10}{100}$

$\frac{10}{100} \cdot 100 % = 10 %$

$1 k m = 100000 c m$

$\frac{1}{100000} \cdot 100 % = 0, 001 %$

$\frac{50}{100000} = \frac{5}{10000}$

$\frac{5}{10000} \cdot 100 % = 0, 05 %$

5