Ajar contains 0.25 liter of apple juice and 0.30 liter of grape juice. melissa poured 0.75 liter of pineapple juice into the jar. she then drank 0.20 liter of the mixture.

I think the first thing you do to the first answer you add 0.25 and 0.30 and it will equal 0.55 and then the next answer you will have to subtract 0.75 and 0.20 so the answer will be 0.55 again.