Please help What percentage of students scored between 50 and 70 points on the exam? Round your answer to the nearest tenth of a percent. I need the last one and second to last questions. PLEASE

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?