A zoo offers unlimited drink refills to visitors who purchase its souvenir cup The cup and the first fill cost 10 and refills after that are 2 each The expression 10 2r represents the total cost of the cup and r refills 1 A family visited the zoo several times over a summer That summer they paid 30 for one cup and multiple refills How many refills did they buy 2 A visitor has 18 to spend on drinks at the zoo today and buys a souvenir cup How many refills can they afford during the visit 3 Another visitor spent 10 on this deal Did they buy any refills Explain how you know