180 g of water was added to 600 g of a 40% salt solution. Find the percentage of salt in the new solution.

Given:
m (salt solution) = 600 g;
salt solution 40%;
Topped up with 180 g of water;
Find:% salt in a new solution?
Decision:
1) Find the mass of salt, at 100% solution:
m (salt) = 600 g * 40% / 100%;
m (salt) = 600 * 2/5 = 240 g;
2) Added 180 g of water:
600 + 180 = 780 g – the mass of the new, formed solution;
3) Find the percentage of salt in the new solution, for this you need to divide the mass of salt by the mass of the new solution formed:
240/780 * 100% = 0.307 * 100% = 30.7%;
Answer: 30.7% new solution.