Which pair of complex numbers has a real-number product? 0 (1 +31(61) 0 (1 + 31) (2 - 31) (1 + 3(1 - 31) O (1 + 31 (31)

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?