I see what you're saying.

Still, we don't know what an equitable share is since you paid what you had available, not what your total share was.

>>So if we follow the spirit of the puzzle, why should you have paid for all the beer?
>>
>
>I didn't pay for all beer, since they already bought it for thier money... I just gave my share...
>
>>>We don't need to assume anything. We have 8 bottles, so each of us drank 8/3.
>>>John gave 5 and drank 8/3, so 7/3 is the difference
>>>Bill gave 3 and drank 8/3, so 1/3 is the difference.
>>>So, they should divide the money in proportion 7:1
>>>
>>>
>>>>If we assume 1$ a beer. If it is !.50 a beer, then you didn't pay enough. Hence the x in my answer.
>>>>
>>>>>>>John brought 5 bottles of beer, Bill brought 3 bottles, when I came. So, we drank this beer together and then I gave them $8 (all I had at this moment). How should they divide this sum?
>>>>>>
>>>>>>$7 for John, / $1 for Bill.
>>>>>
>>>>>And * for you :)