Explanation:
let's just apply common sense :
1/4 is Rosine, so, 800/4 = 200 kg Rosine.
1/5 is Lomelite, so, 800/5 = 160 kg Lomelite.
that leaves 800 - 200 - 160 = 440 kg Anderte
that's really it.×
FYI - when we use fractions for everything, we would say
1/4 = 5/20 Rosine
1/5 = 4/20 Lomelite
that leaves 20/20 - 5/20 - 4/20 = (20-9)/20 = 11/20 if Anderte.