There are two copper and tin alloy ingots. The first contains 40% copper, the second 32% copper.

There are two copper and tin alloy ingots. The first contains 40% copper, the second 32% copper. What weight should these ingots be in order to obtain 8 kg of alloy containing 35% copper after their joint remelting?

Let x be the mass of the first 40% ingot, then the mass of the second 32% ingot will be (8 – x) kg.

Determine the amount of pure copper in the first ingot: 0.40 * x = 0.4x.

Let us express the amount of pure copper in the second alloy: 0.32 (8 – x) = 2.56 – 0.32x.

Since after remelting, 8 kg of a 35% alloy is obtained, we calculate the amount of pure copper in the resulting alloy: 0.35 * 8 = 2.8 (kg). Let’s make the equation:

0.4x + 2.56 – 0.32x = 2.8.

0.08x = 2.8 – 2.56.

0.08x = 0.24.

x = 0.24: 0.08 = 24: 8 = 3 (kg) the mass of a 40% ingot.

8 – 3 = 5 (kg) – the mass of a 32% ingot.