A solution of sodium chloride and water $(40\%$ mass of salt$)$ is added to an evaporator at a rate of $70$ liter$/$minute$.$ The salt does not change the volume, and the water has a density of $1k\frac{g}{l}$iter. A second stream of water and sodium nitrate $(30\%$ salt by mass$)$ is added, $x$ liter$/$minute$.$ The evaporation rate is $y$ liter$/$minute$.$ The solution leaving the evaporator has a ratio of sodium chloride to sodium nitrate of $3$:$2.$ The total salt concentration in the outlet $($sodium chloride and sodium nitrate$)$ cannot be less than $60\%($mass$).$ Solve for $x$ and $y.$