I need help finding the Unit Rate and would like someone to explain it for me so I know how to do it on my own and please no links.​

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.)

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years

Is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis.