a) initially, a lake has 12 pounds of salt in 120 gallons of water

Subject:MathPrice:5.86 Bought15

Share With

a) initially, a lake has 12 pounds of salt in 120 gallons of water. Such a pond has pure water flowing into it at a rate of 6 gallons per minute. The contents of the lake are kept thoroughly mixed, and flow out at a rate of 4 gallons per minute. Set up and solve a differential equation to find the amount of salt y(t) of the mixture at any time t (in minutes). 

I got the answer of y(t)=43200/(160+t^2)

the part i need help with is b

b) What if everything is the same except that instead of pure water flowing in, we have a salt water mixture flowing in at the same rate (6 gallons per minute) with salt concentration of 3 pounds per gallon?