SOLUTION: The radiator truck contains 12 gallons of water. We draw off 3 gallons and replace it with alcohol, then draw off 3 gallons of the mixture and replace it by alcohol, etc., how much

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Question 1085259: The radiator truck contains 12 gallons of water. We draw off 3 gallons and replace it with alcohol, then draw off 3 gallons of the mixture and replace it by alcohol, etc., how much alcohol is in the dinal mixture?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The radiator truck contains 12 gallons of water.
We draw off 3 gallons and replace it with alcohol,
Find the percent alcohol in decimal form, when this is done
3%2F12 = .25
then draw off 3 gallons of the mixture and replace it by alcohol, etc., how much alcohol is in the final mixture?
let x = the percent of alcohol in the final mixture
.25(12-3) + 3 = 12x
.25(9) + 3 = 12x
2.25 + 3 = 12x
5.25 = 12x
x = 5.25/12
x = .4375 * 100 = 43.75% alcohol in the final mixture