Almost impossible to answer if you don't tell us what else they are having in this meal.
the answer is "elbow" :D
When cooked, dried elbow macaroni typically increases in volume by about two to two and a half times. Four cups of dried elbow macaroni will yield approximately 8 to 10 cups of cooked pasta. In terms of weight, this would be about 2 to 2.5 pounds of cooked pasta, depending on the specific cooking method and brand.
Approximately 82 pounds of pasta
Elebow Pasta is just that.... look at your arm from 4 inches below your elbow ( the sharp bend) and 4 inches above your elbow. smooth out your elbow rounding it smooth and that is pretty much what Pasta elbow looks like.
For a main course serving of pasta, you'll need about 1/2 pound of pasta per person. Therefore, for 70 people, you'll need approximately 35 pounds of pasta.
To determine the amount of pasta needed for a pasta salad for 150 people, you must consider the serving size per person. A typical serving size for pasta salad is around 1 cup per person. Therefore, for 150 people, you would need approximately 150 cups of cooked pasta. This translates to roughly 9-10 pounds of dried pasta, depending on the type and shape of pasta used. It's important to adjust this estimate based on the specific recipe and any additional ingredients included in the pasta salad.
so you can eat your pasta with it!!
I would make about 75-80 pounds
One pound of dry pasta equals 2.5 pounds of cooked pasta.
elbow
A good amount of pasta salad for 40 people would be 5 pounds total... just had a party for 40 people and that's what we had, and there was just a bit left over
3 to 5 pounds per person in the south with pasta could use less