Need help Combining percentages of liquids

So I have a question that is probably easy for many people to solve, however I cannot quite figure it out. I am trying to calculate the ABV (Alcohol by Volume) in a mixed drink recipe that I am making for the holidays. So here it goes....

I have two gallons of apple juice to which I am adding a 750 ML bottle of alcohol which is 75.5% alcohol, after adding the alcohol to the total batch what is my new ABV?

The farthest along in the math I can make it is that 750 ML is approximately 20% of one gallon or 10% of the total batch, Am I correct, and directions on how to solve this would be much appreciated! Thanks in advance!

Re: Need help Combining percentages of liquids

Are you SURE you want to do that to perfectly good Apple Juice?!

You DO need a consistent unit.

2 gallons + 750 mL = 8.321 L

750 mL * 75.5% Alcohol = 566.25 mL Alcohol

566.25 mL Alcohol / 8.321 L = 6.8% Alcohol - Not far from your 10%. You're definitely in the "Beer" range.

750 mL / 1 gallon = 19.8% - Not far from your 20%

All in all, with your approximations, you were a little high.

Re: Need help Combining percentages of liquids

Thank you so much for your directions. It will definitely help me in the future! And the drink I am making is seasonal (but great all year) called apple pie moonshine, Not real moonshine as you can tell but does have a delicious taste of apple pie!

Re: Need help Combining percentages of liquids

Well, being a lifetime teetotaler, it does not sound appetizing, but I can do the arithmetic and save the value judgments for later. Don't forget to designate a driver.