Which set of boxes containing tiles with the letters a, b, c, and d meet the following conditions? in box 1, p(a) > p(b)in box 2, p(b) + p(c) + p(d) = 1 in box 3, p(d) = 2p(c)

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?