Is Happyville linear or exponential

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

Which of the following is not a subset of {1,2,3}?

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?