Cum se rezolva acest ex?

Răspuns:
c%=ms/md
1) c%=20/400=2/40=0,05=5%
2)md=(ms/c%)=500/20=25g
msolent=500-25=475g
3)ms=240+60=300g
c%=60/300=6/30=0,2=20%
4)ms=40×80=3200g
msol=3200-80=3120g
5)md=ms-msol=800-600=200g
c%=200/800=2/8=0,25=25%
6)