Biggest Pizza Slice

An 8-inch pizza is cut into 3 equal slices. A 10-inch pizza is cut into 4 equal slices. A 12-inch pizza is cut into 6 equal slices. A 14-inch pizza is cut into 8 equal slices. From which pizza would you take a slice if you want as much pizza as possible?
Source: NCTM Mathematics Teacher, September 2006

Areas of pizza slices
8-inch: \dfrac{\pi\times 4^2}{3}=\dfrac{\pi\times 16}{3}=\dfrac{\pi\times 128}{24}
10-inch: \dfrac{\pi\times 5^2}{4}=\dfrac{\pi\times 25}{4}=\dfrac{\pi\times 150}{24}
12-inch: \dfrac{\pi\times 6^2}{6}=\dfrac{\pi\times 6^2}{6}=\dfrac{\pi\times 144}{24}
14-inch: \dfrac{\pi\times 7^2}{8}=\dfrac{\pi\times 49}{8}=\dfrac{\pi\times 147}{24}
Since \dfrac{150}{24} is the largest fraction, you want to take a slice from the 10-inch pizza.

Answer: 10-inch pizza


About mvtrinh

Retired high school math teacher.
This entry was posted in Problem solving and tagged , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s