I'm honestly not quite sure why, but deleted all my answers and removed a bunch of my brainliest marks, and keeps changing my status. I was Expert but then sometimes it changes to other titles. I have lost all of my answers and a bunch of points. Does someone know why this happened?

Answer asap and if you do you will get brainliest. catherine buys a gallon of ice cream from the store. after taking it home, she eats a fifth of a gallon of ice cream. her sister eats some of the ice cream as well. if two-thirds of the original amount of ice cream is left, then what fraction of a gallon of ice cream did her sister eat?