Find the volume of a pyramid with a square base, where the perimeter of the base is

9.9 cm and the height of the pyramid is 8.6 cm. Round your answer to the nearest

tenth of a cubic centimeter.

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?