1. A tank contains 30 liters of fluid in which 10 grams of salt are dissolved. Brine containing 0.5 gram of salt per liter is then pumped into the tank at the rate of 2 liters per minute and the...

1. A tank contains 30 liters of fluid in which 10 grams of salt are dissolved. Brine containing
0.5 gram of salt per liter is then pumped into the tank at the rate of 2 liters per minute and
the solution mixed well is pumped out of the same rate.
a) Find the number of grams of salt in the tank at any time t in minutes.
b) Find the amount of salt in the tank after 10 minutes.