concentratia / 100 = masa dizolvata / masa solutiei
ms1 = 200 c1= 94%
ms2 = 400 c2= 40%
md1 = c1 x ms1 / 100 = 94x 200/ 100 = 188 grame alcool
md2 = c2 x ms2/100 = 40 x 400 / 100 = 160 grame alcool
c final/100 = (md1+md2) / (ms1+ms2)
c final /100= (188+160) / (200+400) = 384/600 = 0,58
c final = 0,58 x 100 = 58%