1.
ms = 800g, c% = 15%
c% = mdx100/ms
=> md = msxc%/100
= 800x15/100 = 120g
m.apa = ms-md = 800-120 = 680 g
2.
m.apa= ms-md = 100-40 = 60g
c% = 40x100/100 = 40%
3.
ms = md+m.apa = 25+225 = 250 g
c% = 25x100/250 = 10%
4.
idem 1.
5.
ms = md+m.apa = md+320
20 = 100md/(md+320)
=> md = 6400/80 = 80g
=> ms = md+m.apa = 80+320 = 400g
