One head of lettuce should feed 8-10 people, so for 50 people factor 5-6 heads of lettuce.
a billion
100... rabbits? kids? zombies?
if it's only lettuce, then 35 heads ish. could be less. depends on the lettuce, what you're making and how hungery the people are.
13 pounds
1 cut into little pieces
You don't mention whether this is for salad or for sandwiches. For side salads, you would need 12 to 14 medium size heads of lettuce for 100 people.
8 for tomatoes and 4 lettuce heads
8-10 heads of lettuce depending on how much lettuce you use
28 = (70 / 5) * 2
Many websites tell you what it can or cannot eat "hamsterific.com" I feed mine lettuce occasionally with a grain feed from petsmart.
This is dependent on how much each person consumes. There are 16 ounces in a pound. 2.5 pounds = 40 ounces. A head of lettuce typically weighs 12 ounces, which can usually be consumed by 3 - 4 people. SO, if a person consumes 3 ounces of lettuce in a sitting, and there are 40 ounces to be had...about 13 people can be fed.
One cup of shredded Romaine lettuce is about 47 grams. Since a head of Romaine is never the same size, it is best to go on weight. So for 200 people you should allow 50g per serving or 1,000 grams or 1 kilogram or 2.2 pounds of Romaine to feed your guest.