Calculate the mass fraction of salt in the solution if another 20 g of salt was dissolved in 430 g

Calculate the mass fraction of salt in the solution if another 20 g of salt was dissolved in 430 g of a solution with a mass fraction of salt of 25%.

Given:
m1 solution (salt) = 430 g
ω1 (salt) = 25%
m2 (salt) = 20 g

Find:
ω3 (salt) -?

Solution:
1) m1 (salts) = ω1 (salts) * m1 solution (salts) / 100% = 25% * 430/100% = 107.5 g;
2) m3 (salt) = m1 (salt) + m2 (salt) = 107.5 + 20 = 127.5 g;
3) m3 solution (salt) = m1 solution (salt) + m2 (salt) = 430 + 20 = 450 g;
4) ω3 (salt) = m3 (salt) * 100% / m3 solution (salt) = 127.5 * 100% / 450 = 28.33%.

Answer: The mass fraction of salt is 28.33%.