Alcohol!

[teamcool]

Can anyone explain to me how (for example) a 330ml bottle of lager contains 5% alcohol and a 1litre bottle of the same brand lager contains the same amount of alcohol. I sort of understand it but not completely.

[Loosehead]

It's a percentage ie a proportion out of 100. The size of the container is irrelevant so 5% just means that 5/100ths of the total are alcohol or to reduce to it's smallest fraction 1/20th. So in a 330ml bottle there is 16.5ml of alcohol but in a 1 litre bottle there is 50ml of alcohol.

[bernardo]

It does not contain the same "amount".  It contains the same proportion.

[landie]

Imagine theat you are diluting a cordial with water and putting it into different sized cups. You may prepare a large jugfull so that the dilution is consistent, it wont be any different when you've served different amounts.

[teamcool]

Cheers those were all better than my friends explanations!

[druiaghtagh]

In simple terms, i think it means by volume