3. serena is the manager of the coffee shop. the amount of money she earns is represented by the equation = 21ℎ, where ℎ is the number of hours serena works, and is the amount of money she earns. how much more money does serena make an hour than gabe?

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?