I would do 4.5 pounds of potaato
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 would need about 10,000lbs of tato to feed that many booties
About 80 pounds
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.
I would make 38-40 pounds
40 pounds
Are they having other vegetables. If so, then about 18 pounds of potato.
I would use about 60 pounds potato for 200 average people.
It depends on the size of the bags and the size of the potatoes.
It depends what else they are eating. If a normal 3 veg and meat meal, then about 25 pounds of potato.
I normally use 1 oz of instant potatoes per person. This should make a 1/2 cup serving.