Question

A small glass holds 180 ml. How many glasses can be filled from a 2 litre bottle?

Answer 1

If you can assume that the 2l bottle is full, then it holds 2000ml.
2,000 divided by 180 = 11.11.
So the answer is, if you don't spill any, 11 glasses may be filled, with a bit left over.

Answer 2

You will fill 11 glasses. You will have to "go" if you drink all 11 glasses but...

For now just stick with one glass!