See a letter from Ellen about the donation campaign. Your help matters!

sweet potato casserole
How many pounds of sweet potatoes do I need to purchase to make a sweet potato casserole for 150 people? My recipe says after I have enlarged it from the original 3 cups with the program on my computer says I need about 18 quarts of sweet potatoes that are baked. So, my question, how do I determine how many actual potatoes that I need to buy? Thanks
If this is the only potato, you need 35-40 pounds raw per 100. If it is the second potato, and there is stuffing, about 25 pounds per 100.