Equilibrium Concentration After Precipitation

The solubility product constant, $K_{sp}$, for barium sulfate, $\text{BaSO}_4$, is $1.1 \times 10^{-10}$. A 50.0 mL sample of 0.020 M $\text{BaCl}_2$ is mixed with a 50.0 mL sample of 0.030 M $\text{Na}_2\text{SO}_4$. What is the concentration of $\text{Ba}^{2+}$ ions in the solution once equilibrium is established?