Help please

The equation y = 80(3)+ describes the population
growth of snails in a tank at an aquarium where x is the
number of years after 2015 and y represents the
number of snails.

Arestaurant offers a $12 dinner special that has 5 choices for an appetizer, 12 choices for an entrée, and 4 choices for a dessert. how many different meals are available when you select an appetizer, an entrée, and a dessert? a meal can be chosen in nothing ways. (type a whole number.)

Could somebody me with this radical simplification?

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent