10 to 12 potatoes,better to have alittle left over than not enough.
About 80 pounds
you would need about 10,000lbs of tato to feed that many booties
Ask yourself (in the context of the meal overall) how may potatoes could YOU eat. Once you have that in your head you can multiply the number by the number of guests you are intending to feed.
You will need about 1 pound of potatoes per every 3 people.
Figure one large potato per person, or 1-1/2 medium-sized.
35lb of potatoes will be enough especially mashed.
To make cheesy potato casserole most recipes require about 2 pounds of potatoes to feed 8 people. If you are feeding 150 people the recipe would need to be made 19 times over and require 38 pounds of potatoes.
Are they having other vegetables. If so, then about 18 pounds of potato.
I find that 5 medium sized potatoes is good for 3 people. So for 9 it would be 15 potatoes. If you want extra do 20.
You need one and 1/4 potato per person, so: - serving 4 people,= 5 potatoes - serving 10 people,=12 - 13 potatoes.
Allow about a half pound per person. That means you would need about 25 pounds to feed 50 people.
700