Qustions about alcohol proofing?

You know what? You say you're a 'little confused', but out of all the people here on Y!A asking about alcoholic strengths, it seems that you actually understand these things pretty well, so I don't think you're confused at all! Yes, if you have a 'beer bottle' of 40% liquor, it is the equivalent of having 8 bottles of 5% beer. And you're also right that if you mix 1 part of 40%ABV with 3 parts of non-alc mixer, you end up with four parts of 10%ABV drink.

Well done, I'm proud of you, and I mean that sincerely! You've earned your right to go and have a drink. :)

If liquor has 40% alcohol it is 80 proof. Beer and wine don'/t go by proof but by percentage of alcohol. American beers have a 5% limit even on the imports which if you got them in their native country would often be stronger. In some p0laces they have near beer for younger people like in Boulder Colorado the student bars have 3.2 beer and so is the beer in Kansas 3.2. The four x beer I drank in Brisbane Australia was 9% alcohol which not only is stronger than if they export it to America but tastes better. Most wine is 12% to 15% or so but fortified wines can be 20% but they add grain alcohol because naturally fermented wine kills the yeast at 16% or so.

Think of a 100oz bottle,

5% beer would be 5oz of alcohol in the bottle,

40% spirit would be 40oz alcohol in the bottle,

you're right that is 8 times as much,

and 1/4 of the 40% is 10%