A 400 gallon tank initially contains 100 pounds ofsalt in a mixture of 200 gallons of brine

题目

A 400 gallon tank initially contains 100 pounds ofsalt in a mixture of 200 gallons of brine
Another brine containing 2 lb.of salt
per gallon is being added to the tank at a rate of 10 gallons per minute.The
mixed brine in the tank flows out at a rate of 4 gallons per minute.When the
tank is full,how many pounds of salt per gallon will the resulting brine solution
contain?

答案

一个400加仑的罐子中最初装有200加仑的盐溶液,内含100镑盐.另一个盐水容器以每分钟10加仑的速度向罐子中输入盐水,盐水中盐含量为每加仑2镑盐.而盐水罐中的盐水以每分钟4加仑向外排出.请问,当盐水罐装满时,盐溶液中每加仑含多少镑盐.