Two friends, alejandra and mia, agreed to split the check at a restaurant. alejandra ordered $12 worth of food and mia ordered $18 worth. at the end of the meal, alejandra put her $12 contribution on the table, plus a 20% tip and mia put her $18 contribution on the table, plus a 15% tip. the total tip left by alejandra and mia is equal to r\% of the total check for their table, where the "total check" amount does not include the tip. what is r?