Question

Ce cantitate de zahar trebuie adaugatapeste 100g solutie de concentratie 5% pentru a obtine o concentratie de 15%?

Answer 1

c1 = md1/ms1 * 100
md1 = 100*5/100 = 5 g zahăr
md2 = md1+x = 5+x
ms2 = ms1+x = 100+x
c2 = md2/ms2*100
15 = (5+x)/(100+x) * 100
500+100x = 1500+15x
85x=1000
x = 11,764 g zahăr adăugat