is drained out at the same rate. Find the concentration K (t) of salt in the tank as a function of t. 11. A 200 gallon tank initially contains 100 gallons of water with 20 pounds of salt. A salt solution with 1/4 pound of salt per gallon is added to the tank at 4 gal/min, and the resulting mixture is drained out at 2 gal/min. Find the quantity of salt in the tank as it's about to overflow. 12. Suppose water is added to a tank at 10 gal/min, but leaks out at the rate of 1/5 gal/min for each