Can I have some help with this?

Exercise 2. A 200-gal tank contains 100 gal of pure water. At time t = 0, a salt-water solution containing 0.5 1b/gal of salt enters the tank at the rate of 5 gal/min, and the mixture, which is kept uniform by stirring, is withdrawn at the rate of 3 gal/min. (1) Write down a differential equation for the amount of salt in the tank at a time t. (2) Find the amount of salt and its concentration in the tank at a time t. (3) At the time the tank is full, how many pounds of salt will it contain? (4) What would be the limiting concentration of salt at infinity time if the tank had infinity capacity