Răspuns:
La problema 3).
a).ms=400g
c=28%
md=?
m,apă =?
ms=md+m,apă
c=(md×100)÷ms
md=(c×ms)÷100
md=(28×400)÷100=112g
m,apă =400-112=288g,apă
b).
ms=2kg=2000g
c=15%
md=?
m,apă =?
md=(c×ms)÷100
md=(15×2000)÷100
md=300g
m,apă =ms-md
m,apă =2000-300=1700g=1,7kg apă
c).ms1=100g
c1=10%
md1=(c1×ms1)÷100
md1=(10×100)÷100
md1=10g
ms2=300g
c2=30%
md2=?
md2 =(c2×ms2)÷100
md2=(30×300)÷100
md2=90 g
ms=ms1+ms2
ms=100+300=400g
md=md1+md2
md=10+90=100g
c=?
c=(md×100)÷ms
c=(100×100)÷ 400
c=25%
