A piece of copper-zinc alloy weighing 36 kg contains 45% copper. How much copper would you need to add

| January 2, 2021 | education

A piece of copper-zinc alloy weighing 36 kg contains 45% copper. How much copper would you need to add to this piece to get a 60% copper alloy after remelting?

1. According to the problem statement, a piece of alloy has a mass of 36 kg and contains 45% copper.
Find the weight of the copper.
45% = 45/100 of the total.
36/100 * 45 = 16.2 kg.
2. Let X kg be the amount of copper to be added.
Then the total amount of copper will be equal to (X + 16.2) kg.
The weight of the alloy piece becomes (X + 36) kg.
After remelting, an alloy with a copper content of 60% is obtained.
60% = 60/100 = 6/10 of the total.
3. We get the equation.
(X + 16.2) / (X + 36) = 6/10.
6 * (X + 36) = 10 * (X + 16.2).
4 * X = 216 – 162.
4 * X = 54.
X = 54/4.
X = 13.5 kg.
Answer: You need to add 13.5 kg of copper.



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