Cameron is going to the carnival. the price of admission to the carnival is $6.50, and each ride costs an additional 0.75 cents. if cameron can spend at most $20.00 at the carnival, which inequality represents all the possible values of r rides cameron can go on? a) 0.75 + 6.50r ≤ 20.00 b) 0.75 + 6.50r ≥ 20.00 c) 6.50 + 0.75r ≤ 20.00 d) 6.50 + 0.75r ≥ 20.00