The alloy is composed of copper, zinc and lead. It contains 64% copper, 32.8% zinc.

The alloy is composed of copper, zinc and lead. It contains 64% copper, 32.8% zinc. How many kilograms of copper, zinc and lead should be taken to obtain an alloy weighing 0.75 tons?

1. Determine how much copper will be contained in the alloy. We take this mass as a and make up the proportion:

0.75 t – 100%, and t – 64%;

0.75: a = 100: 64;

a = (0.75 x 64): 100;

a = 0.48 t;

2. Determine how much zinc will be contained in the alloy. We take this mass as a and make up the proportion:

0.75 t – 100%, and t – 32.8%;

0.75: a = 100: 32.8;

a = (0.75 x 32.8): 100;

a = 0.246 t;

3. Determine how much lead the alloy will contain:

0.75 – 0.48 – 0.246 = 0.024 t.

Answer: 0.48 tons of copper, 0.246 tons of zinc and 0.024 tons of lead will be contained in the alloy.