No question is dumb, but.. chicken fajita recipe
I found this recipe in Food for Fifty:

1/4 cup Vegetable oil
10 lb (EP) Chicken white meat, cut into strips
3 oz (EP Garlic, minced
1 qt Lime juice
2 cups Water
2 oz Chicken base
3/4 oz Cilantro leaves, whole, finely chopped (see Notes)
1 Tbsp Pepper, black
1 tsp Red pepper, crushed
1 1/2 Tbsp Salt
2 lb 6 oz (EP) Onions, sliced
12 oz (EP) Green bell peppers, cut in 1-inch long strips
8 oz (EP) Red bell peppers, cut in 1-inch long strips
8 oz (EP) Yellow bell peppers, cut in 1-inch long strips
50 10-inch or 100 6-inch Flour tortillas

What does "(EP)" mean? And is this a reasonable amount for fifty middle aged adults?

Oh, I got it now: Edible Portion. Found it on google. I'm also thinking I'd have to double the recipe for my friends too....

Also found "AP" means As Purchased among others.

I would double the various bell peppers and use the 6 inch tortillas, they are neater than the larger ones. This would be OK if you also have rice and beans and a nice salad (maybe guacamole? too); but I would tend to go with 15 pounds chicken and increase everything else in proportion, and still add the side dishes.

Here in my area of Texas, we use boneless thighs. Juicier and more chicken flavor.