Anyone know the answer?

Shiny white dental insurance costs $258 per year. approximately one-third of insured people need a filling, which averages $110 each. 80% of insured people get a preventive check-up each year, and the average cost of this visit is $95. if you consider shiny white’s income and expenses, what is the expected value of each insured customer?

The size of a certain cell is 2.5*10^-9m. another cell is 1.5*10^3 times larger. how large is the larger cell in scientific notation?

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.)