80 g of solution contains 9% salt. How many grams of water should be poured into this solution so that it contains 6% salt?

1. Let’s calculate how much salt is contained in 80 grams of solution.

80 g * 9%: 100% = 7.2 g.

2. Determine the mass of the solution, in which 7.2 grams of salt is 6%.

7.2 g.: 6% * 100% = 120 g.

3. Let’s calculate how many grams of water should be poured into this solution so that it contains 6% salt.

120 g – 80 g = 40 g.

Answer. In order for the resulting solution to contain 6% salt, 40 grams of water must be added to the original solution.