1) (3,4), 2) (1,9), 3) (4,4)
Answer:
30 each of 23% bars and 18 each of 79% bars
Step-by-step explanation:
If x is the number of 1 kg 23% copper bars, and y is the number of 1 kg 79% copper bars, then:
x + y = 48
0.23x + 0.79y = 0.44(48)
Substituting and solving:
0.23x + 0.79(48-x) = 0.44(48)
0.23x + 37.92 - 0.79x = 21.12
16.8 = 0.56x
x = 30
y = 48 - x
y = 18
You need 30 each of 23% bars and 18 each of 79% bars.