c,final=(md1+md2+md)x100/( ms1+ms2+md)
c1=2%
ms1=500g-------> md1= c1xms1/100= 10g
c2= 10%
ms2= 260g----> md2= c2xms2/100= 26g
md1+md2+md= 10+26+115=>151g
ms1+ms2+md= 500+260+115=>875g
c,final= 151x100/875=17,26%
c,m= n/V(l)= md/MxVs, unde Vs(l)= roxms/1000 ,mdx10³/Mx(roxms)=151x10³/58,5x1,2x875.....................calculeaza !!!!