ms1=150g
c1=20%
c=15%
ma= masa de apă adăugată
[tex]c1 = \frac{md}{ms1} \times 100 \\ md = \frac{c1 \times ms1}{100} \\ md = \frac{20 \times 150}{100} = 30g[/tex]
[tex]c = \frac{md}{ms} \times 100 \\ ms = \frac{md \times 100}{c} \\ ms = \frac{30 \times 100}{15} = 200g[/tex]
ms=ms1+ma
ma=ms-ms1=200-150=50g
