3. Joan has an employee discount of 15% off at StuffMart. She needs to buy 4 packages of hot dogs and 3 packages of buns for her cookout. A package of hot dogs is $2.50 and the cheapest buns are $0.50, while the most expensive "fancy" buns are $4.50. If b is the cost of a package of buns, she can model her purchase as c(b) = 0.85(3b + 10) or c(b) = (3b +10) - 0.15(3b + 10) 3. What would her total purchase price be if buns cost $1.507 b. What is the domain of this function? C. What is the range of this function?​