150 grams of twenty percent sugar solution added 30 grams of sugar, find the mass fraction

150 grams of twenty percent sugar solution added 30 grams of sugar, find the mass fraction of the substance in the resulting solution.

Given:
m (solution) = 150 g
m2 (sugar) = 30 g
W1 = 20%
Find:
W2 (substances) =?
Solution:
1) Let’s find how much substance (sugar) was originally.
m substance = W x m solution
m substance = 0.2 x 150 = 30 g.
2) Find how much the total substance (sugar) has become.
30 + 30 = 60 g.
3) Find how much the total solution has become.
150 + 30 = 180 g
4) Find the mass fraction of the substance in the new solution.
W = (m substance: m solution) x 100%
W = (60: 180) x 100% = 33.3%
Answer: W2 (substances) = 33.3%.