[tex]\text{Notam cu x pretul initial.}\\
x+\dfrac{20}{100}\cdot x+\dfrac{10}{100}\left(x+\dfrac{20}{100}\cdot x\right)=264\\
x+\dfrac{x}{5}+\dfrac{1}{10}\left(x+\dfrac{x}{5}\right)=264\\
\dfrac{6x}{5}+\dfrac{6x}{50}=264|\cdot 50\\
60x+6x=13200\\
66x=13200\\
\boxed{x=200\ lei}\\
R: \text{Pretul initial a fost de 200 de lei.}[/tex]