3.
md = 20 g zahar , m.apa = 380 g
stim ca ms = md+m.apa = 20+380 = 400 g solutie
a) stim ca c% = mdx100/ms
= 20x100/400 = 5%
b)
m.apa finala = 380/2 = 140 g
=> c% = 20x100/140 = 1,43%
so;lutie mai diluata
4.
nr. md ms m.apa c%
1 60 400 340 0,15
2. 40 200 160 5%
3. 100 250 150 40