As a part of a main entree, I would make 5 pounds of beans
six pounds of dry beans
it entirely depends on how much these 12 people eat!
I would do 22 pounds of beans
I would make 12 pounds
45 pounds will do it.
I would serve 11 pounds
I would serve 4 oz per person. So 5 pounds for 20 people.
I would make 3.5 pounds
Are they ONLY eating beans, -If other items are on the menu then YOU need to tell us to get a proper answer. If they are only having beans I would make about 100 pounds of beans.
I would use 25 pounds of fresh green beans for 100 people
Your answer depends on the type of bean you want to serve, and whether it not it is the main course, or a side dish. As a side dish, for example, a mix of soup beans measuring about half a cup per serving would be enough.
A half a cup of baked beans is a serving. To serve 100 people, you would need about 50 cups of baked beans. You might want to make a little more to account for people taking more than one serving.