A 150 gallon tank initially contains 70 gallons of pure water. Water with a concentration of c pounds of salt per gallon is added to the tank at 2 ga l/m in., and the resulting solution leaves at a rate of 1 ga l/m in. Find the quantity, Q(t), of pounds of salt in the tank for times 0≤t≤80. (Hint: Your function Q(t) will be in terms of the variable
t and the parameter c.)