$A.$  

Obliczamy, ile powinien zapłacić Zbyszek: 

$\frac{5}{{\sout{12}}^1}\cdot {\sout{37,20}}^{3,10}=$   $5\cdot 3,10=15,50$  

 

 

$B.$  

$\frac{1}{3}:\frac{1}{12}=\frac{1}{{\sout{3}}^1}\cdot \frac{{\sout{12}}^4}{1}=4$  

 

$C.$  

$37,20\cdot \frac{1}{6}=37,20:6=$   $\left(36+1,20\right):6=$  

$=36:6+1,20+;6=6+0,20=6,20\ne 6,60$  

 

$D.$  

$\frac{1}{12}:\frac{1}{6}=\frac{1}{12}\cdot \frac{6}{1}=\frac{6}{12}=\frac{1}{2}$  

Odpowiedź:

C