Răspuns :
Buna seara!
Date
c1=5%
ms1=200g
c2=15%
ms2=300g
Cerinta
c3=?%
c1/100=md1/ms1⇒md1=c1×ms1/100⇒md1=5×200/100=10g
c2/100=md2/ms2⇒md2=c2×ms2/100⇒md2=15×300/100=45g
c3/100=md3/ms3
md3=ms1+ms2=10+45=55g
ms3=ms1+ms2=200+300=500g
c3/100=55/500⇒c3=11%
Succes!