There are 12 empty juice bottles. you drank 8 bottles of juice. i drank the rest. what fraction did i drink?

If the other person drank 8 bottles, that means that there were 4 bottles left
(12 - 8 = 4 bottles)
So you drank 4 out of 12, or 4/12 of the bottles, which simplifies to 1/3 of the bottles.