Question 1130690
9 people, 6 fluid ounces each
Total of 54 fluid ounces of soup.


Amount of needed water:  4.75 cups

{{{4.75*cups*8(fluidounces/cup)=38*fluidounces_of_water}}}


If the rest of the soup will be filled volume from other ingredients, then those will account for:
{{{54-38=16}}},  16 fluid ounces, or about 2 cups.