ms1 = 500 g , c1% = 25%
md = 100 g , m.apa = p(apa)xV(apa) = 1x350 = 350 g apa
stim ca c% = mdx100/ms
=> md1 = ms1xc1%/100 = 500x25/100
= 125 g sare
=> md.final = md1 + md = 125+100 = 225 g
=> ms.final = ms1 + md + m.apa = 500+100+350 = 950 g sol
c%finala = md.finalx100/ms.final
= 225x100/925 = 23,68%