Question 1173226
x kg of 0.20 Cu
100-x kg of 0.60 Cu
that has to make 100 kg of 0.44 copper, which is 44 kg pure copper.

0.20x+0.60(100-x)=44
0.20x+60-0.60x=44
-0.40x=-16
x=40 kg of 20% (8 gm of pure)
100-x=60 kg of 60% (36 gm of pure)