In tyrone's science class he is studing cells. cell a divides every 30 minutes. if tyrone starts with two cells, how many cells will he have in 3 hours?

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?