a) 30% liczby 400

$30\%\cdot 400=\frac{30}{{\sout{100}}^1}\cdot {\sout{400}}^4=120$

 

b) 45% liczby 120

$45\%\cdot 120=\frac{45}{{\sout{100}}^5}\cdot {\sout{120}}^6=\frac{{\sout{45}}^9\cdot 6}{{\sout{5}}^1}=54$ $45\%\cdot 120=\frac{45}{{\sout{100}}^5}\cdot {\sout{120}}^6=\frac{{\sout{45}}^9\cdot 6}{{\sout{5}}^1}=54$

 

c) 130% liczby 250

$130\%\cdot 250=\frac{130}{{\sout{100}}^2}\cdot {\sout{250}}^5=\frac{{\sout{130}}^{65}\cdot 5}{{\sout{2}}^1}=325$

 

d) 12,5% liczby 800

$12,5\%\cdot 800=\frac{12,5}{{\sout{100}}^1}\cdot {\sout{800}}^8=100$

 

e) 0,35% liczby 1200

$0,35\%\cdot 1200=\frac{0,35}{{\sout{100}}^1}\cdot {\sout{1200}}^{12}=4,2$

 

f) 33¹/₃% liczby 90

$33\frac{1}{3}\%\cdot 90=\frac{33\frac{1}{3}}{{\sout{100}}^{10}}\cdot {\sout{90}}^9=\frac{33\frac{1}{3}\cdot 9}{10}=\frac{\frac{100}{{\sout{3}}^1}\cdot {\sout{9}}^3}{10}=\frac{{\sout{300}}^{30}}{{\sout{10}}^1}=30$