[tex]x=cantitatea \; de \; grau \\ x*80\% - \frac{80x}{100} =\frac{4x}{5} \;Kg\;faina \\ \\ \frac{4x}{5}*120\% =\frac{4x}{5}* \frac{120}{100}= \frac{4x}{5}* \frac{6}{5}= \frac{24x}{25} \;Kg \; de \; paine \\ \\ Dar \;\;\; \frac{24x}{25} \;Kg \; de \; paine = 4800 \;Kg \; de \; paine. \\ \\ => \;x=4800* \frac{25}{24} =200*25=5000\;Kg\;de\;grau [/tex]