c/100= md/ms
In aceasta problema, md ramane constant, doar ms se modifica
-calculez md din solutia initiala
20/100=md/250--> md=50gKOH
A.md=50g, ms= 250+200=450
c =50x100/450..........................calculeaza
B. md=50, ms= 250+500
c= 50x100/ 750............................calculeaza
C. md=50 ms= 250+1000
c= 50X100/ 1250...........................CALCULEAZA
D.CONTINUA ...................................................