$a)17\%\text{liczby}42$

$17\%\cdot 42=\frac{17}{{\sout{100}}^{50}}\cdot {\sout{42}}^{21}=\frac{17\cdot 21}{50}=\frac{357}{50}=7\frac{7}{50}=7\frac{14}{100}=7,14$

 

$b)29\%\text{liczby}36$

$29\%\cdot 36=\frac{29}{{\sout{100}}^{25}}\cdot {\sout{36}}^9=\frac{29\cdot 9}{25}=\frac{261}{25}=10\frac{11}{25}=10\frac{44}{100}=10,44$

 

$c)85\%\text{liczby}0,8$

$85\%\cdot 0,8=\frac{85}{{\sout{100}}^{25}}\cdot \frac{{\sout{8}}^2}{10}=\frac{85}{25}\cdot \frac{{\sout{2}}^1}{{\sout{10}}^5}=\frac{85}{25}\cdot \frac{1}{5}=\frac{85}{125}=0,68$

 

$d)13,5\%\text{liczby}180$

$13,5\%\cdot 180=\frac{13,5}{{\sout{100}}^5}\cdot {\sout{180}}^9=\frac{27}{10}\cdot 9=2,7\cdot 9=24,3$

 

$e)2,6\%\text{liczby}85$

$2,6\%\cdot 85=\frac{2,6}{100}\cdot 85=\frac{2,6}{100}\cdot 5\cdot 17=\frac{13}{100}\cdot 17=\frac{221}{100}=2,21$

 

$f)17,5\%\text{liczby}12,8$

$17,5\%\cdot 12,8=\frac{17,5}{100}\cdot 12,8=\frac{35}{200}\cdot 12,8=\frac{448}{200}=\frac{224}{100}=2,24$

 

$g)124\%\text{liczby}45$

$124\%\cdot 45=\frac{124}{{\sout{100}}^{20}}\cdot {\sout{45}}^9=\frac{{\sout{124}}^{31}}{{\sout{20}}^5}\cdot 9=\frac{31\cdot 9}{5}=\frac{279}{5}=55\frac{4}{5}=55\frac{8}{10}=55,8$

 

$h)120,5\%\text{liczby}80$

$120,5\%\cdot 80=\frac{120,5}{{\sout{100}}^5}\cdot {\sout{80}}^4=\frac{120,5}{5}\cdot 4=\frac{482}{5}=\frac{964}{10}=96,4$

 

$i)302\%\text{liczby}10,5$

$302\%\cdot 10,5=\frac{302}{100}\cdot 10,5=\frac{3171}{100}=31,71$