I am guessing it's seven because 2.81 rounds to 3 and 3.72 rounds to 4. So 3+4=7
The option A is the right answer
Sorry im a little late but here's how i did it.
Hope this helps! :)
Given:
20 ounces of water
someone finishes 55% of water
What is left?
20 × 0.55 (55% =

= 0.55)
11
20 - 11 = 9
There are 9 ounces of water left