To a 50% sodium chloride solution, the mass of which is 900 g, 100 g of a 15% sodium

To a 50% sodium chloride solution, the mass of which is 900 g, 100 g of a 15% sodium chloride solution was added to determine the concentration of the solution.

Sodium chloride: NaCl.
Progress in solving the problem:
1 Calculation of the mass of the solute of the 1st solution.
2 Calculation of the mass of the solute of the 2nd solution.
3 Calculation of the mass of the solute after merging the two solutions.
4 Calculation of the mass of the solution after draining.
5 Calculation of the mass fraction of the substance in the resulting solution.
Solution:
1 50 * 900/100 = 450g.
2 100 * 15/100 = 15g.
3 450 + 15 = 465g.
4,900 + 100 = 1000g.
5 W = 465/1000 * 100 = 46.5% – the answer.