2 kg of copper with tin contains 40% copper. How much tin needs to be added to this alloy to make

2 kg of copper with tin contains 40% copper. How much tin needs to be added to this alloy to make the resulting alloy 16% copper?

Let’s calculate how much copper is contained in the first alloy:

1 kg = 1000 g,

2 kg = 2 * 1000 = 2000 g,

0.4 * 2000 = 800 g of copper.

The new copper alloy will also contain 800 grams.

Let’s calculate the mass of the new alloy, if it contains 16% copper:

800: 0.16 = 5000 g.

Find out how much tin needs to be added to the alloy:

5000 – 2000 = 3000 g of tin.

Answer: 3000 g of tin must be added to the alloy.