Răspuns:
c3= md3x100/ms3, unde md3=md1+md2
ms3= ms1+ms2
md1=c1xms1/100=10x50/100g= 5g
md2=c2xms2/100= 30x200/1`00g=60g
ms3= 250g
md3=65g
c3=65x100/250=26%
Explicație: