a)
m.apa= 340g , md= 60g
=> ms = md+m.apa = 340+60 = 400g
c% = mdx100/ms = 60x100/400 = 15%
b)
notam cu a = m.apa.evaporata
=> ms1 = ms-a = 400-a
=> 24 = 60x100/(400-a)
=> a = 3600/24 = 150 g apa evaporata
