Relatiile necesare:
c/100= md/ms, ms= md+m,apa
md este acelasi atat in prima solutie, cat si in a doua; difera doar ms si anume ms2 va fi mai mic ca ms1, iar ms2-ms1= m,apa evaporata
c1/100= md1/ms1
5/100= md1/ 150---> md1= 7,5g
c2/100=md2/ms2 unde md2=md1
25/100= 7,5/ms2---> ms2-=30g <ms1=150g
m,apa evaporata _ =150-30=120g
