A 100 liter barrel of vinegar is 8% acetic acid. Before it can be bottled and used in cooking, the acidity must be reduced to 5% by diluting it with pure water. In order to produce 64 liters of usable vinegar, how many liters of vinegar from the barrel and how many liters of pure water should be combined?

I am doing guessing and checking right now but could someone show me how to make an equation to get the answer?

8/100

4/ 50+X = 1/20

2/ 25+X= 1/20

I am trying to get to 64 liters and i am sure there must be a better way to get to the anwer.

Thanks

Vicky.