Bunuel
Bill and Ted split an excellent pizza with a 20-inch diameter. Bill ate 2/5 of the pizza; Ted ate 1/4. If there are 3 and a half slices left over, what was the area, in square inches, of each individual slice?
A. 2π
B. 5π
C. 10π
D. 20π
E. 40π
Kudos for a correct solution. VERITAS PREP OFFICIAL SOLUTION:Answer: (C)
This is a two-step problem: if you want to solve for the area of each slice, you first need to know how many slices there are in one whole pizza. If Bill ate 2/5 of the pizza and Ted ate 1/4, their combined fraction (adding them with the least common denominator of 20) of 13/20 represents the portion of the pizza eaten. The 3.5 left over slices therefore are the remaining 7/20 of the pizza. You can set up a simple ratio to solve for the total number of slices (or just logic it out): 7/20= 3.5/total . Cross-multiply to get 7(total) = 3.5(20), and solving for the total you get 10.
Once you’ve determined there are 10 slices in a full pizza, the area of each slice is just one-tenth of the total area. We were given the diameter (20 inches), from which we can solve for radius (10) and area (π∗10^2=100π). Dividing this total area by ten slices, you get an area of 10π per slice.