SOLUTION: A barrel contains 30 gallons of 40% antifreeze. How many gallons of an 80% antifreeze solution should be added to make the barrel contain 50% antifreeze?

Question 338654: A barrel contains 30 gallons of 40% antifreeze. How many gallons of an 80% antifreeze solution should be added to make the barrel contain 50% antifreeze?
Answer by nerdybill(7384) (Show Source): You can put this solution on YOUR website!
A barrel contains 30 gallons of 40% antifreeze. How many gallons of an 80% antifreeze solution should be added to make the barrel contain 50% antifreeze?
.
Let x = gallons of 80% antifreeze added
then
.40(30) + .80x = .50(30+x)
12 + .80x = 15 + .50x
12 + .30x = 15
.30x = 3
x = 10 gallons

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