100 ml apa = 100 g apa (ro = 1 g/ml)
c% = 6% = mdx100/ms
=> ms = md + m.apa = a + 100
a = ms - 100
=> 6 = ax100/(100+a)
=> 6(100+a) = 100a
600 + 6a = 100a
=> a = 600/94 = 6,38 g
=> ms (alcool absolut) = ax100/99,5
=> ms = 6,38x100/99,5 = 6,415 g sol alcool absolut
daca se doreste si Vs stim ca ro alcool = 0,78 g/ml
=> Vs = ms / ro = 6,415 / 0,78 = 8,22 ml sol alcool absolut
