Răspuns:
m impură=250kg
Explicație:
Salutare! ʕ•ᴥ•ʔ
[tex]m_{pura}=200kg[/tex]
[tex]p=80\%[/tex]
[tex]m_{impura}=?[/tex]
[tex]m_{impura}=\frac{m_{pura}\times100}{p}[/tex]
[tex]m_{impura}=\frac{200kg\times100}{80} =\frac{20000kg}{80} =250kg[/tex]
Succes! (◕‿-)