Răspuns:
c=(md/ms)×100-->20/100=md/700-->md=(20×700)/100-->md=140g
c=(md/ms)×100-->35/100=140/ms--->ms=(100×140)/35-->ms2=400g
ms2=md+m2(H2O)--->400=140+m2(H2O)--->m2(H2O)=260g
ms1=md+m1(H2O)-->700=140+m1(H2O)-->m1(H2O)=560g
mH2O evaporată=m1(H2O)-m2(H2O)=560-260=300g