To 150 g of a 5% salt solution, another 15 g of salt was added. The mass fraction of salt in the resulting solution is ..

1) Calculation of the mass of the solute salt in its solution. To do this, multiply the mass of the solution by the mass fraction of the substance and multiply by one hundred percent.
2) Calculation of the mass of the solute after adding salt. Add the mass of the solute of the original solution and the mass of the added salt.
3) Calculation of the mass of the entire solution after adding salt.
4) Calculation of the mass fraction of salt in the resulting solution.
Decision:
1) 150 * 5/100 = 7.5g.
2) 7.5 + 15 = 22.5g.
3) 150 + 15 = 165g.
4) 22.5 / 165 * 100 = 13.6% – the answer.