ms1 = 250g , c1 = 15%
ms2 = 200g , c2 = 18%
m.apa = 300g
stim ca c% = mdx100/ms
=> md1 = ms1xc1/100 = 250x15/100 = 37,5 g
=> md2 = ms2xc2/100 = 200x18/100 = 36 g
=> md.tot = 37,5 + 36 = 73,5 g
ms.tot = ms1+ms2+m.apa = 250+200+300 = 750 g
=> c%.final = md.totx100/ms.tot
= 73,5x100/750 = 9,8%