This is actually a bit of a trick question, as several European countries including: Armenia, Belgium, Bulgaria, Czech Republic, Denmark, France, Moldova, Netherlands, Norway, Poland, and Russia have no formal laws on what age people are allowed to consume alcoholic beverages. However, the map above (with a few errors) shows what age people have to be buy various types of alcohol.
According to Wikipedia these are the ages you’re allowed to purchase alcohol by country in Europe: