ms1 = 40g, c1% = 40%
c%final = 60%
stim ca c% = mdx100/ms
=> md1 = ms1xc1/100 = 40x40/100 = 16 g
md.final = md1 + md.adaugat = 16+md.ad.
ms.final = ms1+md.adaugat = 40+md.ad
c%final = md.finalx100/ms.final
=> 60 = (16+md.ad)100/(40+md.ad)
=> md.ad = 800/40 = 20 g sare adaugata
facem proba:
md.final = 16+20 = 36g
ms.final = 40+20 = 60g
=> c%final = 36x100/60 = 60%, deci verifica calculele de mai sus