Answer:
16 fluid ounces
Step-by-step explanation:
Mario buys 8 containers of soup.
Each container has 18 fluid ounces.
In other words, there are a total of:

144 fluid ounces.
Each of the 9 people got the same amount of soup. In other words, divided equally, each person got:

16 fluid ounces of soup.
And we're done!
They have the exact same value so you just divide by 1
45.34 X 3= 136.02
212.52 - 136.02= 76.50
76.50/3= 25.50
the answer is $25.50