To answer this question, find the unit rates for price per pizza. You can do this by simply dividing the diameter (which is directly proportional to the area of the circle) by the price:
[tex]\frac{16}{12.99} = $1.23[/tex]
[tex]\frac{8}{6} = 1.33[/tex]
The 8in pizza has a greater cost per unit, and is therefore lesser of a value. Your answer is the 16in pizza for $12.99 because it has a cost per unit of $1.23.
