40 kilograms alloy of 20 % copper and 60 kilograms of alloy of 70 % copper is combined to get 100 kg of 50 % copper alloy
Solution:
Th final alloy is 100 kg
Let "x" be the alloy of 20 % copper
Then, (100 - x) is the alloy of 70 % copper
Therefore,we can say,
"x" kilograms alloy of 20 % copper and (100 - x) kilograms of alloy of 70 % copper is combined to get 100 kg of 50 % copper alloy
Therefore, we frame a equation as:
[tex]x \times 20 \% + (100-x) \times 70 \% = 100 \times 50 \%\\\\x \times \frac{20}{100} + (100-x) \times \frac{70}{100} = 100 \times \frac{50}{100}\\\\0.2x + (100-x) \times 0.7 = 0.5 \times 100\\\\0.2x + 70 - 0.7x = 50\\\\-0.5x = -20\\\\x = 40[/tex]
Thus 40 kilograms of 20 % copper
Then, 100 - x = 100 - 40 = 60
60 kilograms of 70 % copper is used
