lnilialiy 5 grams of salt are dissolved inlo 15 liters of water. Brine with concentration of salt 3 grams per liter is added al a rate of 2 lilers per minute. The tank is well mixed and drained at 2 liters per minute. a. Lel a: be the amount of salt, in grams, in the solulion after t minutes have elapsed. Find a formula for the rate of change in the amount of sail, aim/cit, in terms of the amount of salt in the solution x. d: E : gramslminute b. Find a formula for the amount of salt, in grams, after 1' minutes have elapsed. $(t) : grams c. How long must the process continue until there are exactly 20 grams of salt in the tank? minutes