4 kg of water was added to 8 kg of a 60% salt solution. What was the percentage of salt in the solution after that?

Let’s calculate the weight of the salt in the solution:

8 * 60% / 100% = 4.8 kg of salt.

After adding 4 kg of water, the weight of the salt in the solution did not change, and the total weight of the solution became 12 kg.

Then, we find the percentage of salt in the new solution using the proportion:

12 kg – 100%;

4.8 kg – x%.

x = 4.8 * 100% / 12 = 40%.

Answer: 12 kg of solution contains 40% salt.