Question 242963
If a round 8-inch diameter pizza serves two students, how many students should two 12-inch diameter pizzas serve? 

a. 9 b. 8 c. 6 d. 4 e. NG


Since one 8-inch pizza serves 2 students, then this means that a pizza with an area of {{{16pi}}} serves 2 students  


A pizza with a diameter of 12 inches has an area of {{{36pi}}}. Therefore, 2 pizzas with diameters of 12 iches each both have a total area of {{{72pi}}} squared inches.


Using proportions, we can determine how many students two 12-inch diameter pizzas can feed. By making the amount of students equal to S, we get the following:


{{{2/S = 16pi/72pi}}}


Cross-multiplying, we get:  {{{S16pi = 144pi}}} 


{{{S  =  144pi/(16pi)}}}


{{{S  =  9cross(144pi)/cross(16pi)}}}


Therefore, S, or the amount of students that two 12-inch diameter pizzas will serve is{{{highlight_green(9)}}} {{{highlight_green(CHOICE_A)}}}