What is the percentage concentration of the solution if 20 g of sugar are dissolved in 180 ml of water?

Given:
V (H2O) = 180 ml
m (sugar) = 20 g
ρ (H2O) = 1 g / ml

To find:
ω (sugar) -?

Decision:
1) Calculate the mass of water:
m (H2O) = ρ (H2O) * V (H2O) = 1 * 180 = 180 g;
2) Calculate the mass of the resulting solution:
m solution (sugar) = m (sugar) + m (H2O) = 20 + 180 = 200 g;
3) Calculate the mass fraction of sugar in the resulting solution:
ω (sugar) = m (sugar) * 100% / m solution (sugar) = 20 * 100% / 200 = 10%.

Answer: The mass fraction of sugar in the resulting solution is 10%.