A 1000-liter tank contains 500 L of water with a salt concentration of 10 g/L. Water with a salt concentration of 50 g/L flows into the tank at a rate of Rin = 80 L/min. The fluid mixes instantaneously and is pumped out at a specified rate Rout. Let y(t) denote the quantity of salt in the tank at time t.

Assuming that Rout = 120 L/min, find y(t). Then calculate the tank volume and the salt concentration at t = 10 min.