A bread company has a total of 12 packages of buns to sell. Each package of buns contains 6 buns and sells for $2.50. The cost of the buns, in dollars, is a function of the number of packages bought.
Which of the following values are NOT in the domain of the function described?
a) -2
b) 0
c) 0.5
d) 6
e) 14