For 25 people, 10-11 lbs. of salad should be plenty. However, just to be sure, 12 lbs. would be more than plenty.
I would make 125 pounds of salad.
1 Gallon of potato salad feeds about 30 people, so 3.33 Gallons.
You should plan for about 1/2 cup per person. That make 250 cups which would be just under 16 gallons of potato salad.
500
The normal serving is considered to be 4 ounces. You have twice that amount. You will probably have lots of leftovers!
over 500 people
About $500
I would believe that 500 calories is 500 calories. So yes, they are equal in calorie amount.
That is approximately 520 gm .
about 60-70 pounds
1.10, but I don't know what currency.
People have been recorded weighing as much as 1100 pounds (500 kg).