SOLUTION: How do you solve: How many gallons of 25% alcohol solution should be mixed with 6 gallons of 5o% alcohol solution to obtain a 30% alcohol solution? Thank you!

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Question 281530: How do you solve:
How many gallons of 25% alcohol solution should be mixed with 6 gallons of 5o% alcohol solution to obtain a 30% alcohol solution?
Thank you!
Answer by Mathematicians(84) (Show Source):
You can put this solution on YOUR website!
This one is often a tricky one, I see this problem every once in a while:
please note that 25 percent is .25, however, if we multiply both sides by a hundred, this becomes 25. You will see what I mean below:
We will need to set up the equation as, percent times how much we put in:

Now for explaining how I got this:
We need 25 percent of X gallons, I put x because it doesn't say how many. We also need 50 percent of 6 gallons, which will make a total of 30 percent of (x + 6), we get x + 6 by adding up x and 6. If I were to multiply both sides by a hundred the percent signs get taken off and unfortunately there is technical problems when using decimal so I had to remove them early, now to solve:

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We will need 24 gallons of 25% alcohol with 6 gallons of 50% alcohol to make 30% alcohol solution.