Answer:
He had 11.25L of paint Left!
Explanation:
25/2.5= 10
If He used all the paint it would have taken him 10 hours
but he only took 5.5 hours
Lets break 5.5 into two parts 5, and 0.5
5*2.5= 12.5
and
0.5*2.5= 1.25
Add them both to get how much paint he used (13.75L)
Now subtract 13.75 from te total (25)
25-13.75=11.25
Hopes this makes sense, have a nice day :)