SOLUTION: A barrel contains 100 gallons of solution that initially has a concentration of 10 grams of salt/gallon. At the end of each minute, one gallon of solution is removed from the barre

Question 789246: A barrel contains 100 gallons of solution that initially has a concentration of 10 grams of salt/gallon. At the end of each minute, one gallon of solution is removed from the barrel, discarded, and replaced with one gallon of pure water, and well-mixed. How many minutes pass before the solution has a concentration of less than 1 gram of salt per gallon?
Answer by josgarithmetic(39618) (Show Source): You can put this solution on YOUR website!
This is exponential decay. You could treat is like the rate is a 1% decay each period, here the period being one minute. During each period, the concentration is 0.99 of what it was in the previous period.

Starting at 10 for 10 grams/gallon, is the concentration of salt present after n number of periods.

You are looking for something about like and want to find n.
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