concentratia / 100 = masa dizolvata / masa solutie
in solutia initiala, masa solutiei = 300 grame si masa dizolvata = c x msol / 100 = 10 x 300 / 100 = 30 grame
adaugand zahar, va creste masa dizolvata cu x grame, masa de solutie tot cu x grame
c1 / 100 = (md+x)/ (ms+x)
c1 = 16%
md = 30
16/ 100 = (30+x) / (300+x)
100(30+x) = 16(300+x)
3000 +100 x = 4800 +16x
84 x = 1800
x = 1800/84 = 21,4285 grame
