Can someone please help me with this question? Thank you. Please no links or steal the points, I really need help!

With number 11 ( show how you got the answer)

Charlie is at an amusement park that has 18 different rides. each ride costs $1.75. the function c(r) = 1.75r represents the total amount of money that charlie will spend if he goes on r rides, but he never goes on the same one more than once. what domain and range are reasonable for the function?

7+(3n++8) what is the answer to this?