It takes 3 hours for marty and cora to weed a garden. how long will it take 6 people to weed the same garden if they all work at the same constant rate? explain.

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?