For those who answered my request for help with cooking rice for 100 I did a
small test run that worked very well.

Preheated oven to 375F.

Heated 1 tbsp. oil in a 6 quart stainless steel pot. Added 2 cups converted
rice and stirred about 3 minutes 'till good & hot. Added 3.5 cups boiling
water and 1 tsp. salt. Stirred well. Covered with a tight fitting lid and
put in the oven for 15 minutes.
Resisted the temptation to peek.

Rice was perfect - light & fluffy.

It expanded to make a measured 9 cups and filled not quite 1/2 the pot. If
I use an average serving size of 3/4 cup of finished rice per person this
quantity would serve at least 12 people. So for 100 people I would need to
start with about 8 times or 16 cups of raw rice. This is a mixed group -
not huge eaters.

Note that the quantity of water was considerably less than the often quoted
ratio of 1 rice to 2 water. However I have always found that on the
stovetop I need to use only about 1 to 1.5 for dry and fluffy rice. Maybe
some like it wetter?

Thanks to those who replied to my previous post.

BeeCee