Pickett

Haha, that's kind of fun to wrap your head around...

well...

Depends...

...a lot...

@Cygnet I think something is wrong with your solution, as one of the requirements is that "18 of us did not drink water." by your answer, you have 8 that drank nothing, 7 that drank only wine, and 11 that drank beer and wine...which totals 26 people that did not drink water.

I'm guessing it's because I missed this piece of the assumption: "who drank beer and water but not wine were as many as possible". I'll give it another go with the non-drinkers included and that piece and see what I come up with.

Approach

Yes...I can.

FWIW

Nevermind...misunderstood the OP (again).

I assumed my answer was along the right lines, but I was too lazy to actually find the true minimum with it...thanks for doing the dirty work!