8.
ms = 40 g , c%= 20%
c% = mdx100/ms
=> md = msxc%/100 = 40x20/100 = 8 g zahar
m.apa = ms-md = 40 - 8 = 32 g
9.
ms = 25 g , md = 1,5 g
c% = mdx100/ms = 1,5x100/25 = 6%
