To 160 g of a 13% salt solution was added 300 ml of vrd. Find the mass fraction of salt in the resulting solution.

The mass of salt in the original solution.
m (salt) = W (salt) • m (solution) / 100% = 13% • 160 g / 100% = 20.8 g.
The mass of the solution after adding water.
m (solution) = m (original solution) + m (H2O) = 300 g + 160 g = 460 g.
Let us determine the mass fraction of salt after diluting the solution.
W (salt) = m (salt) / m (solution) • 100% = 20.8 g / 460 g • 100% = 4.5%.