S2
c% = mdx100/ms
= 30x100/600 = 5%
m.apa = ms-md = 600-30 = 570 g
S3
ms=md+m.apa = md+270
25 = 100md/(md+270)
=> 25md + 6750 = 100 md
=> md = 90 g
=> ms = 90+270 = 360 g
S4
ms = mdx100/c%
= 90x100/30 = 300g
=> m.apa = ms-md = 300-90 = 210g
S5
ms=270+30 = 300 g
=> c% = 30x100/300 = 10%
S6
idem S4
S7
md = ms-m.apa = 800-640 = 160g
=> c% = 160x100/800 = 20%
