Explanation

The mixture contains 12% copper, which means that 12% of the mixture's weight is copper.

We want to find out how many kg of mixture is required to get 69 kg of copper.

Let's say the weight of the mixture is x kg.

Since 12% of the mixture is copper, the weight of copper in the mixture is 12% of x, which is 0.12x.

We are told that the weight of copper is 69 kg, so we can set up the equation:

0.12x = 69

To solve for x, we can divide both sides by 0.12:

x = 69 / 0.12

x = 575

So, the weight of the mixture is 575 kg.